/*----------------------------------------------------------------------------/
/  FatFs - Generic FAT Filesystem Module  R0.13                               /
/-----------------------------------------------------------------------------/
/
/ Copyright (C) 2017, ChaN, all right reserved.
/
/ FatFs module is an open source software. Redistribution and use of FatFs in
/ source and binary forms, with or without modification, are permitted provided
/ that the following condition is met:
/
/ 1. Redistributions of source code must retain the above copyright notice,
/    this condition and the following disclaimer.
/
/ This software is provided by the copyright holder and contributors "AS IS"
/ and any warranties related to this software are DISCLAIMED.
/ The copyright owner or contributors be NOT LIABLE for any damages caused
/ by use of this software.
/
/----------------------------------------------------------------------------*/

#ifndef WIN32_LEAN_AND_MEAN
#define WIN32_LEAN_AND_MEAN 1
#endif /*WIN32_LEAN_AND_MEAN*/

#include "ff.h"     /* Declarations of FatFs API */
#include "diskio.h" /* Declarations of device I/O functions */

/*--------------------------------------------------------------------------

   Module Private Definitions

---------------------------------------------------------------------------*/

#if FF_DEFINED != 87030 /* Revision ID */
#error Wrong include file (ff.h).
#endif

/* ASCII code support macros */
#define IsUpper(c) ((c) >= 'A' && (c) <= 'Z')
#define IsLower(c) ((c) >= 'a' && (c) <= 'z')
#define IsDigit(c) ((c) >= '0' && (c) <= '9')

/* Additional file attribute bits for internal use */
#define AM_VOL 0x08  /* Volume label */
#define AM_LFN 0x0F  /* LFN entry */
#define AM_MASK 0x3F /* Mask of defined bits */

/* Additional file access control and file status flags for internal use */
#define FA_SEEKEND 0x20  /* Seek to end of the file on file open */
#define FA_MODIFIED 0x40 /* File has been modified */
#define FA_DIRTY 0x80    /* FIL.buf[] needs to be written-back */

/* Name status flags in fn[11] */
#define NSFLAG 11      /* Index of the name status byte */
#define NS_LOSS 0x01   /* Out of 8.3 format */
#define NS_LFN 0x02    /* Force to create LFN entry */
#define NS_LAST 0x04   /* Last segment */
#define NS_BODY 0x08   /* Lower case flag (body) */
#define NS_EXT 0x10    /* Lower case flag (ext) */
#define NS_DOT 0x20    /* Dot entry */
#define NS_NOLFN 0x40  /* Do not find LFN */
#define NS_NONAME 0x80 /* Not followed */

/* Limits and boundaries */
#define MAX_DIR 0x200000      /* Max size of FAT directory */
#define MAX_DIR_EX 0x10000000 /* Max size of exFAT directory */
#define MAX_FAT12 \
  0xFF5 /* Max FAT12 clusters (differs from specs, but correct for real DOS/Windows behavior) */
#define MAX_FAT16 \
  0xFFF5 /* Max FAT16 clusters (differs from specs, but correct for real DOS/Windows behavior) */
#define MAX_FAT32 0x0FFFFFF5 /* Max FAT32 clusters (not specified, practical limit) */
#define MAX_EXFAT 0x7FFFFFFD /* Max exFAT clusters (differs from specs, implementation limit) */

/* FatFs refers the FAT structure as simple byte array instead of structure member
/ because the C structure is not binary compatible between different platforms */

#define BS_JmpBoot 0      /* x86 jump instruction (3-byte) */
#define BS_OEMName 3      /* OEM name (8-byte) */
#define BPB_BytsPerSec 11 /* Sector size [byte] (WORD) */
#define BPB_SecPerClus 13 /* Cluster size [sector] (BYTE) */
#define BPB_RsvdSecCnt 14 /* Size of reserved area [sector] (WORD) */
#define BPB_NumFATs 16    /* Number of FATs (BYTE) */
#define BPB_RootEntCnt 17 /* Size of root directory area for FAT [entry] (WORD) */
#define BPB_TotSec16 19   /* Volume size (16-bit) [sector] (WORD) */
#define BPB_Media 21      /* Media descriptor byte (BYTE) */
#define BPB_FATSz16 22    /* FAT size (16-bit) [sector] (WORD) */
#define BPB_SecPerTrk 24  /* Number of sectors per track for int13h [sector] (WORD) */
#define BPB_NumHeads 26   /* Number of heads for int13h (WORD) */
#define BPB_HiddSec 28    /* Volume offset from top of the drive (DWORD) */
#define BPB_TotSec32 32   /* Volume size (32-bit) [sector] (DWORD) */
#define BS_DrvNum 36      /* Physical drive number for int13h (BYTE) */
#define BS_NTres 37       /* WindowsNT error flag (BYTE) */
#define BS_BootSig 38     /* Extended boot signature (BYTE) */
#define BS_VolID 39       /* Volume serial number (DWORD) */
#define BS_VolLab 43      /* Volume label string (8-byte) */
#define BS_FilSysType 54  /* Filesystem type string (8-byte) */
#define BS_BootCode 62    /* Boot code (448-byte) */
#define BS_55AA 510       /* Signature word (WORD) */

#define BPB_FATSz32 36     /* FAT32: FAT size [sector] (DWORD) */
#define BPB_ExtFlags32 40  /* FAT32: Extended flags (WORD) */
#define BPB_FSVer32 42     /* FAT32: Filesystem version (WORD) */
#define BPB_RootClus32 44  /* FAT32: Root directory cluster (DWORD) */
#define BPB_FSInfo32 48    /* FAT32: Offset of FSINFO sector (WORD) */
#define BPB_BkBootSec32 50 /* FAT32: Offset of backup boot sector (WORD) */
#define BS_DrvNum32 64     /* FAT32: Physical drive number for int13h (BYTE) */
#define BS_NTres32 65      /* FAT32: Error flag (BYTE) */
#define BS_BootSig32 66    /* FAT32: Extended boot signature (BYTE) */
#define BS_VolID32 67      /* FAT32: Volume serial number (DWORD) */
#define BS_VolLab32 71     /* FAT32: Volume label string (8-byte) */
#define BS_FilSysType32 82 /* FAT32: Filesystem type string (8-byte) */
#define BS_BootCode32 90   /* FAT32: Boot code (420-byte) */

#define BPB_ZeroedEx 11      /* exFAT: MBZ field (53-byte) */
#define BPB_VolOfsEx 64      /* exFAT: Volume offset from top of the drive [sector] (QWORD) */
#define BPB_TotSecEx 72      /* exFAT: Volume size [sector] (QWORD) */
#define BPB_FatOfsEx 80      /* exFAT: FAT offset from top of the volume [sector] (DWORD) */
#define BPB_FatSzEx 84       /* exFAT: FAT size [sector] (DWORD) */
#define BPB_DataOfsEx 88     /* exFAT: Data offset from top of the volume [sector] (DWORD) */
#define BPB_NumClusEx 92     /* exFAT: Number of clusters (DWORD) */
#define BPB_RootClusEx 96    /* exFAT: Root directory start cluster (DWORD) */
#define BPB_VolIDEx 100      /* exFAT: Volume serial number (DWORD) */
#define BPB_FSVerEx 104      /* exFAT: Filesystem version (WORD) */
#define BPB_VolFlagEx 106    /* exFAT: Volume flags (BYTE) */
#define BPB_ActFatEx 107     /* exFAT: Active FAT flags (BYTE) */
#define BPB_BytsPerSecEx 108 /* exFAT: Log2 of sector size in unit of byte (BYTE) */
#define BPB_SecPerClusEx 109 /* exFAT: Log2 of cluster size in unit of sector (BYTE) */
#define BPB_NumFATsEx 110    /* exFAT: Number of FATs (BYTE) */
#define BPB_DrvNumEx 111     /* exFAT: Physical drive number for int13h (BYTE) */
#define BPB_PercInUseEx 112  /* exFAT: Percent in use (BYTE) */
#define BPB_RsvdEx 113       /* exFAT: Reserved (7-byte) */
#define BS_BootCodeEx 120    /* exFAT: Boot code (390-byte) */

#define DIR_Name 0            /* Short file name (11-byte) */
#define DIR_Attr 11           /* Attribute (BYTE) */
#define DIR_NTres 12          /* Lower case flag (BYTE) */
#define DIR_CrtTime10 13      /* Created time sub-second (BYTE) */
#define DIR_CrtTime 14        /* Created time (DWORD) */
#define DIR_LstAccDate 18     /* Last accessed date (WORD) */
#define DIR_FstClusHI 20      /* Higher 16-bit of first cluster (WORD) */
#define DIR_ModTime 22        /* Modified time (DWORD) */
#define DIR_FstClusLO 26      /* Lower 16-bit of first cluster (WORD) */
#define DIR_FileSize 28       /* File size (DWORD) */
#define LDIR_Ord 0            /* LFN: LFN order and LLE flag (BYTE) */
#define LDIR_Attr 11          /* LFN: LFN attribute (BYTE) */
#define LDIR_Type 12          /* LFN: Entry type (BYTE) */
#define LDIR_Chksum 13        /* LFN: Checksum of the SFN (BYTE) */
#define LDIR_FstClusLO 26     /* LFN: MBZ field (WORD) */
#define XDIR_Type 0           /* exFAT: Type of exFAT directory entry (BYTE) */
#define XDIR_NumLabel 1       /* exFAT: Number of volume label characters (BYTE) */
#define XDIR_Label 2          /* exFAT: Volume label (11-WORD) */
#define XDIR_CaseSum 4        /* exFAT: Sum of case conversion table (DWORD) */
#define XDIR_NumSec 1         /* exFAT: Number of secondary entries (BYTE) */
#define XDIR_SetSum 2         /* exFAT: Sum of the set of directory entries (WORD) */
#define XDIR_Attr 4           /* exFAT: File attribute (WORD) */
#define XDIR_CrtTime 8        /* exFAT: Created time (DWORD) */
#define XDIR_ModTime 12       /* exFAT: Modified time (DWORD) */
#define XDIR_AccTime 16       /* exFAT: Last accessed time (DWORD) */
#define XDIR_CrtTime10 20     /* exFAT: Created time subsecond (BYTE) */
#define XDIR_ModTime10 21     /* exFAT: Modified time subsecond (BYTE) */
#define XDIR_CrtTZ 22         /* exFAT: Created timezone (BYTE) */
#define XDIR_ModTZ 23         /* exFAT: Modified timezone (BYTE) */
#define XDIR_AccTZ 24         /* exFAT: Last accessed timezone (BYTE) */
#define XDIR_GenFlags 33      /* exFAT: General secondary flags (BYTE) */
#define XDIR_NumName 35       /* exFAT: Number of file name characters (BYTE) */
#define XDIR_NameHash 36      /* exFAT: Hash of file name (WORD) */
#define XDIR_ValidFileSize 40 /* exFAT: Valid file size (QWORD) */
#define XDIR_FstClus 52       /* exFAT: First cluster of the file data (DWORD) */
#define XDIR_FileSize 56      /* exFAT: File/Directory size (QWORD) */

#define SZDIRE 32  /* Size of a directory entry */
#define DDEM 0xE5  /* Deleted directory entry mark set to DIR_Name[0] */
#define RDDEM 0x05 /* Replacement of the character collides with DDEM */
#define LLEF 0x40  /* Last long entry flag in LDIR_Ord */

#define FSI_LeadSig 0      /* FAT32 FSI: Leading signature (DWORD) */
#define FSI_StrucSig 484   /* FAT32 FSI: Structure signature (DWORD) */
#define FSI_Free_Count 488 /* FAT32 FSI: Number of free clusters (DWORD) */
#define FSI_Nxt_Free 492   /* FAT32 FSI: Last allocated cluster (DWORD) */

#define MBR_Table 446 /* MBR: Offset of partition table in the MBR */
#define SZ_PTE 16     /* MBR: Size of a partition table entry */
#define PTE_Boot 0    /* MBR PTE: Boot indicator */
#define PTE_StHead 1  /* MBR PTE: Start head */
#define PTE_StSec 2   /* MBR PTE: Start sector */
#define PTE_StCyl 3   /* MBR PTE: Start cylinder */
#define PTE_System 4  /* MBR PTE: System ID */
#define PTE_EdHead 5  /* MBR PTE: End head */
#define PTE_EdSec 6   /* MBR PTE: End sector */
#define PTE_EdCyl 7   /* MBR PTE: End cylinder */
#define PTE_StLba 8   /* MBR PTE: Start in LBA */
#define PTE_SizLba 12 /* MBR PTE: Size in LBA */

/* Post process after fatal error on file operation */
#define ABORT(fs, res)     \
  {                        \
    fp->err = (BYTE)(res); \
    LEAVE_FF(fs, res);     \
  }

/* Reentrancy related */
#if FF_FS_REENTRANT
#if FF_USE_LFN == 1
#error Static LFN work area cannot be used at thread-safe configuration
#endif
#define LEAVE_FF(fs, res) \
  {                       \
    unlock_fs(fs, res);   \
    return res;           \
  }
#else
#define LEAVE_FF(fs, res) return res
#endif

/* Definitions of volume - partition conversion */
#if FF_MULTI_PARTITION
#define LD2PD(vol) VolToPart[vol].pd /* Get physical drive number */
#define LD2PT(vol) VolToPart[vol].pt /* Get partition index */
#else
#define LD2PD(vol) (BYTE)(vol) /* Each logical drive is bound to the same physical drive number */
#define LD2PT(vol) 0           /* Find first valid partition or in SFD */
#endif

/* Definitions of sector size */
#if (FF_MAX_SS < FF_MIN_SS) ||                                                           \
    (FF_MAX_SS != 512 && FF_MAX_SS != 1024 && FF_MAX_SS != 2048 && FF_MAX_SS != 4096) || \
    (FF_MIN_SS != 512 && FF_MIN_SS != 1024 && FF_MIN_SS != 2048 && FF_MIN_SS != 4096)
#error Wrong sector size configuration
#endif
#if FF_MAX_SS == FF_MIN_SS
#define SS(fs) ((UINT)FF_MAX_SS) /* Fixed sector size */
#else
#define SS(fs) ((fs)->ssize) /* Variable sector size */
#endif

/* Timestamp */
#if FF_FS_NORTC == 1
#if FF_NORTC_YEAR < 1980 || FF_NORTC_YEAR > 2107 || FF_NORTC_MON < 1 || FF_NORTC_MON > 12 || \
    FF_NORTC_MDAY < 1 || FF_NORTC_MDAY > 31
#error Invalid FF_FS_NORTC settings
#endif
#define GET_FATTIME() \
  ((DWORD)(FF_NORTC_YEAR - 1980) << 25 | (DWORD)FF_NORTC_MON << 21 | (DWORD)FF_NORTC_MDAY << 16)
#else
#define GET_FATTIME() get_fattime()
#endif

/* File lock controls */
#if FF_FS_LOCK != 0
#if FF_FS_READONLY
#error FF_FS_LOCK must be 0 at read-only configuration
#endif
typedef struct {
  FATFS* fs; /* Object ID 1, volume (NULL:blank entry) */
  DWORD clu; /* Object ID 2, containing directory (0:root) */
  DWORD ofs; /* Object ID 3, offset in the directory */
  WORD ctr;  /* Object open counter, 0:none, 0x01..0xFF:read mode open count, 0x100:write mode */
} FILESEM;
#endif

/* SBCS up-case tables (\x80-\xFF) */
#define TBL_CT437                                                                                 \
  {                                                                                               \
    0x80, 0x9A, 0x45, 0x41, 0x8E, 0x41, 0x8F, 0x80, 0x45, 0x45, 0x45, 0x49, 0x49, 0x49, 0x8E,     \
        0x8F, 0x90, 0x92, 0x92, 0x4F, 0x99, 0x4F, 0x55, 0x55, 0x59, 0x99, 0x9A, 0x9B, 0x9C, 0x9D, \
        0x9E, 0x9F, 0x41, 0x49, 0x4F, 0x55, 0xA5, 0xA5, 0xA6, 0xA7, 0xA8, 0xA9, 0xAA, 0xAB, 0xAC, \
        0xAD, 0xAE, 0xAF, 0xB0, 0xB1, 0xB2, 0xB3, 0xB4, 0xB5, 0xB6, 0xB7, 0xB8, 0xB9, 0xBA, 0xBB, \
        0xBC, 0xBD, 0xBE, 0xBF, 0xC0, 0xC1, 0xC2, 0xC3, 0xC4, 0xC5, 0xC6, 0xC7, 0xC8, 0xC9, 0xCA, \
        0xCB, 0xCC, 0xCD, 0xCE, 0xCF, 0xD0, 0xD1, 0xD2, 0xD3, 0xD4, 0xD5, 0xD6, 0xD7, 0xD8, 0xD9, \
        0xDA, 0xDB, 0xDC, 0xDD, 0xDE, 0xDF, 0xE0, 0xE1, 0xE2, 0xE3, 0xE4, 0xE5, 0xE6, 0xE7, 0xE8, \
        0xE9, 0xEA, 0xEB, 0xEC, 0xED, 0xEE, 0xEF, 0xF0, 0xF1, 0xF2, 0xF3, 0xF4, 0xF5, 0xF6, 0xF7, \
        0xF8, 0xF9, 0xFA, 0xFB, 0xFC, 0xFD, 0xFE, 0xFF                                            \
  }
#define TBL_CT720                                                                                 \
  {                                                                                               \
    0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8A, 0x8B, 0x8C, 0x8D, 0x8E,     \
        0x8F, 0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99, 0x9A, 0x9B, 0x9C, 0x9D, \
        0x9E, 0x9F, 0xA0, 0xA1, 0xA2, 0xA3, 0xA4, 0xA5, 0xA6, 0xA7, 0xA8, 0xA9, 0xAA, 0xAB, 0xAC, \
        0xAD, 0xAE, 0xAF, 0xB0, 0xB1, 0xB2, 0xB3, 0xB4, 0xB5, 0xB6, 0xB7, 0xB8, 0xB9, 0xBA, 0xBB, \
        0xBC, 0xBD, 0xBE, 0xBF, 0xC0, 0xC1, 0xC2, 0xC3, 0xC4, 0xC5, 0xC6, 0xC7, 0xC8, 0xC9, 0xCA, \
        0xCB, 0xCC, 0xCD, 0xCE, 0xCF, 0xD0, 0xD1, 0xD2, 0xD3, 0xD4, 0xD5, 0xD6, 0xD7, 0xD8, 0xD9, \
        0xDA, 0xDB, 0xDC, 0xDD, 0xDE, 0xDF, 0xE0, 0xE1, 0xE2, 0xE3, 0xE4, 0xE5, 0xE6, 0xE7, 0xE8, \
        0xE9, 0xEA, 0xEB, 0xEC, 0xED, 0xEE, 0xEF, 0xF0, 0xF1, 0xF2, 0xF3, 0xF4, 0xF5, 0xF6, 0xF7, \
        0xF8, 0xF9, 0xFA, 0xFB, 0xFC, 0xFD, 0xFE, 0xFF                                            \
  }
#define TBL_CT737                                                                                 \
  {                                                                                               \
    0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8A, 0x8B, 0x8C, 0x8D, 0x8E,     \
        0x8F, 0x90, 0x92, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x80, 0x81, 0x82, 0x83, 0x84, 0x85, \
        0x86, 0x87, 0x88, 0x89, 0x8A, 0x8B, 0x8C, 0x8D, 0x8E, 0x8F, 0x90, 0x91, 0xAA, 0x92, 0x93, \
        0x94, 0x95, 0x96, 0xB0, 0xB1, 0xB2, 0xB3, 0xB4, 0xB5, 0xB6, 0xB7, 0xB8, 0xB9, 0xBA, 0xBB, \
        0xBC, 0xBD, 0xBE, 0xBF, 0xC0, 0xC1, 0xC2, 0xC3, 0xC4, 0xC5, 0xC6, 0xC7, 0xC8, 0xC9, 0xCA, \
        0xCB, 0xCC, 0xCD, 0xCE, 0xCF, 0xD0, 0xD1, 0xD2, 0xD3, 0xD4, 0xD5, 0xD6, 0xD7, 0xD8, 0xD9, \
        0xDA, 0xDB, 0xDC, 0xDD, 0xDE, 0xDF, 0x97, 0xEA, 0xEB, 0xEC, 0xE4, 0xED, 0xEE, 0xEF, 0xF5, \
        0xF0, 0xEA, 0xEB, 0xEC, 0xED, 0xEE, 0xEF, 0xF0, 0xF1, 0xF2, 0xF3, 0xF4, 0xF5, 0xF6, 0xF7, \
        0xF8, 0xF9, 0xFA, 0xFB, 0xFC, 0xFD, 0xFE, 0xFF                                            \
  }
#define TBL_CT771                                                                                 \
  {                                                                                               \
    0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8A, 0x8B, 0x8C, 0x8D, 0x8E,     \
        0x8F, 0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99, 0x9A, 0x9B, 0x9C, 0x9D, \
        0x9E, 0x9F, 0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8A, 0x8B, 0x8C, \
        0x8D, 0x8E, 0x8F, 0xB0, 0xB1, 0xB2, 0xB3, 0xB4, 0xB5, 0xB6, 0xB7, 0xB8, 0xB9, 0xBA, 0xBB, \
        0xBC, 0xBD, 0xBE, 0xBF, 0xC0, 0xC1, 0xC2, 0xC3, 0xC4, 0xC5, 0xC6, 0xC7, 0xC8, 0xC9, 0xCA, \
        0xCB, 0xCC, 0xCD, 0xCE, 0xCF, 0xD0, 0xD1, 0xD2, 0xD3, 0xD4, 0xD5, 0xD6, 0xD7, 0xD8, 0xD9, \
        0xDA, 0xDB, 0xDC, 0xDC, 0xDE, 0xDE, 0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, \
        0x99, 0x9A, 0x9B, 0x9C, 0x9D, 0x9E, 0x9F, 0xF0, 0xF0, 0xF2, 0xF2, 0xF4, 0xF4, 0xF6, 0xF6, \
        0xF8, 0xF8, 0xFA, 0xFA, 0xFC, 0xFC, 0xFE, 0xFF                                            \
  }
#define TBL_CT775                                                                                 \
  {                                                                                               \
    0x80, 0x9A, 0x91, 0xA0, 0x8E, 0x95, 0x8F, 0x80, 0xAD, 0xED, 0x8A, 0x8A, 0xA1, 0x8D, 0x8E,     \
        0x8F, 0x90, 0x92, 0x92, 0xE2, 0x99, 0x95, 0x96, 0x97, 0x97, 0x99, 0x9A, 0x9D, 0x9C, 0x9D, \
        0x9E, 0x9F, 0xA0, 0xA1, 0xE0, 0xA3, 0xA3, 0xA5, 0xA6, 0xA7, 0xA8, 0xA9, 0xAA, 0xAB, 0xAC, \
        0xAD, 0xAE, 0xAF, 0xB0, 0xB1, 0xB2, 0xB3, 0xB4, 0xB5, 0xB6, 0xB7, 0xB8, 0xB9, 0xBA, 0xBB, \
        0xBC, 0xBD, 0xBE, 0xBF, 0xC0, 0xC1, 0xC2, 0xC3, 0xC4, 0xC5, 0xC6, 0xC7, 0xC8, 0xC9, 0xCA, \
        0xCB, 0xCC, 0xCD, 0xCE, 0xCF, 0xB5, 0xB6, 0xB7, 0xB8, 0xBD, 0xBE, 0xC6, 0xC7, 0xA5, 0xD9, \
        0xDA, 0xDB, 0xDC, 0xDD, 0xDE, 0xDF, 0xE0, 0xE1, 0xE2, 0xE3, 0xE5, 0xE5, 0xE6, 0xE3, 0xE8, \
        0xE8, 0xEA, 0xEA, 0xEE, 0xED, 0xEE, 0xEF, 0xF0, 0xF1, 0xF2, 0xF3, 0xF4, 0xF5, 0xF6, 0xF7, \
        0xF8, 0xF9, 0xFA, 0xFB, 0xFC, 0xFD, 0xFE, 0xFF                                            \
  }
#define TBL_CT850                                                                                 \
  {                                                                                               \
    0x43, 0x55, 0x45, 0x41, 0x41, 0x41, 0x41, 0x43, 0x45, 0x45, 0x45, 0x49, 0x49, 0x49, 0x41,     \
        0x41, 0x45, 0x92, 0x92, 0x4F, 0x4F, 0x4F, 0x55, 0x55, 0x59, 0x4F, 0x55, 0x4F, 0x9C, 0x4F, \
        0x9E, 0x9F, 0x41, 0x49, 0x4F, 0x55, 0xA5, 0xA5, 0xA6, 0xA7, 0xA8, 0xA9, 0xAA, 0xAB, 0xAC, \
        0xAD, 0xAE, 0xAF, 0xB0, 0xB1, 0xB2, 0xB3, 0xB4, 0x41, 0x41, 0x41, 0xB8, 0xB9, 0xBA, 0xBB, \
        0xBC, 0xBD, 0xBE, 0xBF, 0xC0, 0xC1, 0xC2, 0xC3, 0xC4, 0xC5, 0x41, 0x41, 0xC8, 0xC9, 0xCA, \
        0xCB, 0xCC, 0xCD, 0xCE, 0xCF, 0xD1, 0xD1, 0x45, 0x45, 0x45, 0x49, 0x49, 0x49, 0x49, 0xD9, \
        0xDA, 0xDB, 0xDC, 0xDD, 0x49, 0xDF, 0x4F, 0xE1, 0x4F, 0x4F, 0x4F, 0x4F, 0xE6, 0xE8, 0xE8, \
        0x55, 0x55, 0x55, 0x59, 0x59, 0xEE, 0xEF, 0xF0, 0xF1, 0xF2, 0xF3, 0xF4, 0xF5, 0xF6, 0xF7, \
        0xF8, 0xF9, 0xFA, 0xFB, 0xFC, 0xFD, 0xFE, 0xFF                                            \
  }
#define TBL_CT852                                                                                 \
  {                                                                                               \
    0x80, 0x9A, 0x90, 0xB6, 0x8E, 0xDE, 0x8F, 0x80, 0x9D, 0xD3, 0x8A, 0x8A, 0xD7, 0x8D, 0x8E,     \
        0x8F, 0x90, 0x91, 0x91, 0xE2, 0x99, 0x95, 0x95, 0x97, 0x97, 0x99, 0x9A, 0x9B, 0x9B, 0x9D, \
        0x9E, 0xAC, 0xB5, 0xD6, 0xE0, 0xE9, 0xA4, 0xA4, 0xA6, 0xA6, 0xA8, 0xA8, 0xAA, 0x8D, 0xAC, \
        0xB8, 0xAE, 0xAF, 0xB0, 0xB1, 0xB2, 0xB3, 0xB4, 0xB5, 0xB6, 0xB7, 0xB8, 0xB9, 0xBA, 0xBB, \
        0xBC, 0xBD, 0xBD, 0xBF, 0xC0, 0xC1, 0xC2, 0xC3, 0xC4, 0xC5, 0xC6, 0xC6, 0xC8, 0xC9, 0xCA, \
        0xCB, 0xCC, 0xCD, 0xCE, 0xCF, 0xD1, 0xD1, 0xD2, 0xD3, 0xD2, 0xD5, 0xD6, 0xD7, 0xB7, 0xD9, \
        0xDA, 0xDB, 0xDC, 0xDD, 0xDE, 0xDF, 0xE0, 0xE1, 0xE2, 0xE3, 0xE3, 0xD5, 0xE6, 0xE6, 0xE8, \
        0xE9, 0xE8, 0xEB, 0xED, 0xED, 0xDD, 0xEF, 0xF0, 0xF1, 0xF2, 0xF3, 0xF4, 0xF5, 0xF6, 0xF7, \
        0xF8, 0xF9, 0xFA, 0xEB, 0xFC, 0xFC, 0xFE, 0xFF                                            \
  }
#define TBL_CT855                                                                                 \
  {                                                                                               \
    0x81, 0x81, 0x83, 0x83, 0x85, 0x85, 0x87, 0x87, 0x89, 0x89, 0x8B, 0x8B, 0x8D, 0x8D, 0x8F,     \
        0x8F, 0x91, 0x91, 0x93, 0x93, 0x95, 0x95, 0x97, 0x97, 0x99, 0x99, 0x9B, 0x9B, 0x9D, 0x9D, \
        0x9F, 0x9F, 0xA1, 0xA1, 0xA3, 0xA3, 0xA5, 0xA5, 0xA7, 0xA7, 0xA9, 0xA9, 0xAB, 0xAB, 0xAD, \
        0xAD, 0xAE, 0xAF, 0xB0, 0xB1, 0xB2, 0xB3, 0xB4, 0xB6, 0xB6, 0xB8, 0xB8, 0xB9, 0xBA, 0xBB, \
        0xBC, 0xBE, 0xBE, 0xBF, 0xC0, 0xC1, 0xC2, 0xC3, 0xC4, 0xC5, 0xC7, 0xC7, 0xC8, 0xC9, 0xCA, \
        0xCB, 0xCC, 0xCD, 0xCE, 0xCF, 0xD1, 0xD1, 0xD3, 0xD3, 0xD5, 0xD5, 0xD7, 0xD7, 0xDD, 0xD9, \
        0xDA, 0xDB, 0xDC, 0xDD, 0xE0, 0xDF, 0xE0, 0xE2, 0xE2, 0xE4, 0xE4, 0xE6, 0xE6, 0xE8, 0xE8, \
        0xEA, 0xEA, 0xEC, 0xEC, 0xEE, 0xEE, 0xEF, 0xF0, 0xF2, 0xF2, 0xF4, 0xF4, 0xF6, 0xF6, 0xF8, \
        0xF8, 0xFA, 0xFA, 0xFC, 0xFC, 0xFD, 0xFE, 0xFF                                            \
  }
#define TBL_CT857                                                                                 \
  {                                                                                               \
    0x80, 0x9A, 0x90, 0xB6, 0x8E, 0xB7, 0x8F, 0x80, 0xD2, 0xD3, 0xD4, 0xD8, 0xD7, 0x49, 0x8E,     \
        0x8F, 0x90, 0x92, 0x92, 0xE2, 0x99, 0xE3, 0xEA, 0xEB, 0x98, 0x99, 0x9A, 0x9D, 0x9C, 0x9D, \
        0x9E, 0x9E, 0xB5, 0xD6, 0xE0, 0xE9, 0xA5, 0xA5, 0xA6, 0xA6, 0xA8, 0xA9, 0xAA, 0xAB, 0xAC, \
        0xAD, 0xAE, 0xAF, 0xB0, 0xB1, 0xB2, 0xB3, 0xB4, 0xB5, 0xB6, 0xB7, 0xB8, 0xB9, 0xBA, 0xBB, \
        0xBC, 0xBD, 0xBE, 0xBF, 0xC0, 0xC1, 0xC2, 0xC3, 0xC4, 0xC5, 0xC7, 0xC7, 0xC8, 0xC9, 0xCA, \
        0xCB, 0xCC, 0xCD, 0xCE, 0xCF, 0xD0, 0xD1, 0xD2, 0xD3, 0xD4, 0x49, 0xD6, 0xD7, 0xD8, 0xD9, \
        0xDA, 0xDB, 0xDC, 0xDD, 0xDE, 0xDF, 0xE0, 0xE1, 0xE2, 0xE3, 0xE5, 0xE5, 0xE6, 0xE7, 0xE8, \
        0xE9, 0xEA, 0xEB, 0xDE, 0xED, 0xEE, 0xEF, 0xF0, 0xF1, 0xF2, 0xF3, 0xF4, 0xF5, 0xF6, 0xF7, \
        0xF8, 0xF9, 0xFA, 0xFB, 0xFC, 0xFD, 0xFE, 0xFF                                            \
  }
#define TBL_CT860                                                                                 \
  {                                                                                               \
    0x80, 0x9A, 0x90, 0x8F, 0x8E, 0x91, 0x86, 0x80, 0x89, 0x89, 0x92, 0x8B, 0x8C, 0x98, 0x8E,     \
        0x8F, 0x90, 0x91, 0x92, 0x8C, 0x99, 0xA9, 0x96, 0x9D, 0x98, 0x99, 0x9A, 0x9B, 0x9C, 0x9D, \
        0x9E, 0x9F, 0x86, 0x8B, 0x9F, 0x96, 0xA5, 0xA5, 0xA6, 0xA7, 0xA8, 0xA9, 0xAA, 0xAB, 0xAC, \
        0xAD, 0xAE, 0xAF, 0xB0, 0xB1, 0xB2, 0xB3, 0xB4, 0xB5, 0xB6, 0xB7, 0xB8, 0xB9, 0xBA, 0xBB, \
        0xBC, 0xBD, 0xBE, 0xBF, 0xC0, 0xC1, 0xC2, 0xC3, 0xC4, 0xC5, 0xC6, 0xC7, 0xC8, 0xC9, 0xCA, \
        0xCB, 0xCC, 0xCD, 0xCE, 0xCF, 0xD0, 0xD1, 0xD2, 0xD3, 0xD4, 0xD5, 0xD6, 0xD7, 0xD8, 0xD9, \
        0xDA, 0xDB, 0xDC, 0xDD, 0xDE, 0xDF, 0xE0, 0xE1, 0xE2, 0xE3, 0xE4, 0xE5, 0xE6, 0xE7, 0xE8, \
        0xE9, 0xEA, 0xEB, 0xEC, 0xED, 0xEE, 0xEF, 0xF0, 0xF1, 0xF2, 0xF3, 0xF4, 0xF5, 0xF6, 0xF7, \
        0xF8, 0xF9, 0xFA, 0xFB, 0xFC, 0xFD, 0xFE, 0xFF                                            \
  }
#define TBL_CT861                                                                                 \
  {                                                                                               \
    0x80, 0x9A, 0x90, 0x41, 0x8E, 0x41, 0x8F, 0x80, 0x45, 0x45, 0x45, 0x8B, 0x8B, 0x8D, 0x8E,     \
        0x8F, 0x90, 0x92, 0x92, 0x4F, 0x99, 0x8D, 0x55, 0x97, 0x97, 0x99, 0x9A, 0x9D, 0x9C, 0x9D, \
        0x9E, 0x9F, 0xA4, 0xA5, 0xA6, 0xA7, 0xA4, 0xA5, 0xA6, 0xA7, 0xA8, 0xA9, 0xAA, 0xAB, 0xAC, \
        0xAD, 0xAE, 0xAF, 0xB0, 0xB1, 0xB2, 0xB3, 0xB4, 0xB5, 0xB6, 0xB7, 0xB8, 0xB9, 0xBA, 0xBB, \
        0xBC, 0xBD, 0xBE, 0xBF, 0xC0, 0xC1, 0xC2, 0xC3, 0xC4, 0xC5, 0xC6, 0xC7, 0xC8, 0xC9, 0xCA, \
        0xCB, 0xCC, 0xCD, 0xCE, 0xCF, 0xD0, 0xD1, 0xD2, 0xD3, 0xD4, 0xD5, 0xD6, 0xD7, 0xD8, 0xD9, \
        0xDA, 0xDB, 0xDC, 0xDD, 0xDE, 0xDF, 0xE0, 0xE1, 0xE2, 0xE3, 0xE4, 0xE5, 0xE6, 0xE7, 0xE8, \
        0xE9, 0xEA, 0xEB, 0xEC, 0xED, 0xEE, 0xEF, 0xF0, 0xF1, 0xF2, 0xF3, 0xF4, 0xF5, 0xF6, 0xF7, \
        0xF8, 0xF9, 0xFA, 0xFB, 0xFC, 0xFD, 0xFE, 0xFF                                            \
  }
#define TBL_CT862                                                                                 \
  {                                                                                               \
    0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8A, 0x8B, 0x8C, 0x8D, 0x8E,     \
        0x8F, 0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99, 0x9A, 0x9B, 0x9C, 0x9D, \
        0x9E, 0x9F, 0x41, 0x49, 0x4F, 0x55, 0xA5, 0xA5, 0xA6, 0xA7, 0xA8, 0xA9, 0xAA, 0xAB, 0xAC, \
        0xAD, 0xAE, 0xAF, 0xB0, 0xB1, 0xB2, 0xB3, 0xB4, 0xB5, 0xB6, 0xB7, 0xB8, 0xB9, 0xBA, 0xBB, \
        0xBC, 0xBD, 0xBE, 0xBF, 0xC0, 0xC1, 0xC2, 0xC3, 0xC4, 0xC5, 0xC6, 0xC7, 0xC8, 0xC9, 0xCA, \
        0xCB, 0xCC, 0xCD, 0xCE, 0xCF, 0xD0, 0xD1, 0xD2, 0xD3, 0xD4, 0xD5, 0xD6, 0xD7, 0xD8, 0xD9, \
        0xDA, 0xDB, 0xDC, 0xDD, 0xDE, 0xDF, 0xE0, 0xE1, 0xE2, 0xE3, 0xE4, 0xE5, 0xE6, 0xE7, 0xE8, \
        0xE9, 0xEA, 0xEB, 0xEC, 0xED, 0xEE, 0xEF, 0xF0, 0xF1, 0xF2, 0xF3, 0xF4, 0xF5, 0xF6, 0xF7, \
        0xF8, 0xF9, 0xFA, 0xFB, 0xFC, 0xFD, 0xFE, 0xFF                                            \
  }
#define TBL_CT863                                                                                 \
  {                                                                                               \
    0x43, 0x55, 0x45, 0x41, 0x41, 0x41, 0x86, 0x43, 0x45, 0x45, 0x45, 0x49, 0x49, 0x8D, 0x41,     \
        0x8F, 0x45, 0x45, 0x45, 0x4F, 0x45, 0x49, 0x55, 0x55, 0x98, 0x4F, 0x55, 0x9B, 0x9C, 0x55, \
        0x55, 0x9F, 0xA0, 0xA1, 0x4F, 0x55, 0xA4, 0xA5, 0xA6, 0xA7, 0x49, 0xA9, 0xAA, 0xAB, 0xAC, \
        0xAD, 0xAE, 0xAF, 0xB0, 0xB1, 0xB2, 0xB3, 0xB4, 0xB5, 0xB6, 0xB7, 0xB8, 0xB9, 0xBA, 0xBB, \
        0xBC, 0xBD, 0xBE, 0xBF, 0xC0, 0xC1, 0xC2, 0xC3, 0xC4, 0xC5, 0xC6, 0xC7, 0xC8, 0xC9, 0xCA, \
        0xCB, 0xCC, 0xCD, 0xCE, 0xCF, 0xD0, 0xD1, 0xD2, 0xD3, 0xD4, 0xD5, 0xD6, 0xD7, 0xD8, 0xD9, \
        0xDA, 0xDB, 0xDC, 0xDD, 0xDE, 0xDF, 0xE0, 0xE1, 0xE2, 0xE3, 0xE4, 0xE5, 0xE6, 0xE7, 0xE8, \
        0xE9, 0xEA, 0xEB, 0xEC, 0xED, 0xEE, 0xEF, 0xF0, 0xF1, 0xF2, 0xF3, 0xF4, 0xF5, 0xF6, 0xF7, \
        0xF8, 0xF9, 0xFA, 0xFB, 0xFC, 0xFD, 0xFE, 0xFF                                            \
  }
#define TBL_CT864                                                                                 \
  {                                                                                               \
    0x80, 0x9A, 0x45, 0x41, 0x8E, 0x41, 0x8F, 0x80, 0x45, 0x45, 0x45, 0x49, 0x49, 0x49, 0x8E,     \
        0x8F, 0x90, 0x92, 0x92, 0x4F, 0x99, 0x4F, 0x55, 0x55, 0x59, 0x99, 0x9A, 0x9B, 0x9C, 0x9D, \
        0x9E, 0x9F, 0x41, 0x49, 0x4F, 0x55, 0xA5, 0xA5, 0xA6, 0xA7, 0xA8, 0xA9, 0xAA, 0xAB, 0xAC, \
        0xAD, 0xAE, 0xAF, 0xB0, 0xB1, 0xB2, 0xB3, 0xB4, 0xB5, 0xB6, 0xB7, 0xB8, 0xB9, 0xBA, 0xBB, \
        0xBC, 0xBD, 0xBE, 0xBF, 0xC0, 0xC1, 0xC2, 0xC3, 0xC4, 0xC5, 0xC6, 0xC7, 0xC8, 0xC9, 0xCA, \
        0xCB, 0xCC, 0xCD, 0xCE, 0xCF, 0xD0, 0xD1, 0xD2, 0xD3, 0xD4, 0xD5, 0xD6, 0xD7, 0xD8, 0xD9, \
        0xDA, 0xDB, 0xDC, 0xDD, 0xDE, 0xDF, 0xE0, 0xE1, 0xE2, 0xE3, 0xE4, 0xE5, 0xE6, 0xE7, 0xE8, \
        0xE9, 0xEA, 0xEB, 0xEC, 0xED, 0xEE, 0xEF, 0xF0, 0xF1, 0xF2, 0xF3, 0xF4, 0xF5, 0xF6, 0xF7, \
        0xF8, 0xF9, 0xFA, 0xFB, 0xFC, 0xFD, 0xFE, 0xFF                                            \
  }
#define TBL_CT865                                                                                 \
  {                                                                                               \
    0x80, 0x9A, 0x90, 0x41, 0x8E, 0x41, 0x8F, 0x80, 0x45, 0x45, 0x45, 0x49, 0x49, 0x49, 0x8E,     \
        0x8F, 0x90, 0x92, 0x92, 0x4F, 0x99, 0x4F, 0x55, 0x55, 0x59, 0x99, 0x9A, 0x9B, 0x9C, 0x9D, \
        0x9E, 0x9F, 0x41, 0x49, 0x4F, 0x55, 0xA5, 0xA5, 0xA6, 0xA7, 0xA8, 0xA9, 0xAA, 0xAB, 0xAC, \
        0xAD, 0xAE, 0xAF, 0xB0, 0xB1, 0xB2, 0xB3, 0xB4, 0xB5, 0xB6, 0xB7, 0xB8, 0xB9, 0xBA, 0xBB, \
        0xBC, 0xBD, 0xBE, 0xBF, 0xC0, 0xC1, 0xC2, 0xC3, 0xC4, 0xC5, 0xC6, 0xC7, 0xC8, 0xC9, 0xCA, \
        0xCB, 0xCC, 0xCD, 0xCE, 0xCF, 0xD0, 0xD1, 0xD2, 0xD3, 0xD4, 0xD5, 0xD6, 0xD7, 0xD8, 0xD9, \
        0xDA, 0xDB, 0xDC, 0xDD, 0xDE, 0xDF, 0xE0, 0xE1, 0xE2, 0xE3, 0xE4, 0xE5, 0xE6, 0xE7, 0xE8, \
        0xE9, 0xEA, 0xEB, 0xEC, 0xED, 0xEE, 0xEF, 0xF0, 0xF1, 0xF2, 0xF3, 0xF4, 0xF5, 0xF6, 0xF7, \
        0xF8, 0xF9, 0xFA, 0xFB, 0xFC, 0xFD, 0xFE, 0xFF                                            \
  }
#define TBL_CT866                                                                                 \
  {                                                                                               \
    0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8A, 0x8B, 0x8C, 0x8D, 0x8E,     \
        0x8F, 0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99, 0x9A, 0x9B, 0x9C, 0x9D, \
        0x9E, 0x9F, 0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8A, 0x8B, 0x8C, \
        0x8D, 0x8E, 0x8F, 0xB0, 0xB1, 0xB2, 0xB3, 0xB4, 0xB5, 0xB6, 0xB7, 0xB8, 0xB9, 0xBA, 0xBB, \
        0xBC, 0xBD, 0xBE, 0xBF, 0xC0, 0xC1, 0xC2, 0xC3, 0xC4, 0xC5, 0xC6, 0xC7, 0xC8, 0xC9, 0xCA, \
        0xCB, 0xCC, 0xCD, 0xCE, 0xCF, 0xD0, 0xD1, 0xD2, 0xD3, 0xD4, 0xD5, 0xD6, 0xD7, 0xD8, 0xD9, \
        0xDA, 0xDB, 0xDC, 0xDD, 0xDE, 0xDF, 0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, \
        0x99, 0x9A, 0x9B, 0x9C, 0x9D, 0x9E, 0x9F, 0xF0, 0xF0, 0xF2, 0xF2, 0xF4, 0xF4, 0xF6, 0xF6, \
        0xF8, 0xF9, 0xFA, 0xFB, 0xFC, 0xFD, 0xFE, 0xFF                                            \
  }
#define TBL_CT869                                                                                 \
  {                                                                                               \
    0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8A, 0x8B, 0x8C, 0x8D, 0x8E,     \
        0x8F, 0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99, 0x9A, 0x86, 0x9C, 0x8D, \
        0x8F, 0x90, 0x91, 0x90, 0x92, 0x95, 0xA4, 0xA5, 0xA6, 0xA7, 0xA8, 0xA9, 0xAA, 0xAB, 0xAC, \
        0xAD, 0xAE, 0xAF, 0xB0, 0xB1, 0xB2, 0xB3, 0xB4, 0xB5, 0xB6, 0xB7, 0xB8, 0xB9, 0xBA, 0xBB, \
        0xBC, 0xBD, 0xBE, 0xBF, 0xC0, 0xC1, 0xC2, 0xC3, 0xC4, 0xC5, 0xC6, 0xC7, 0xC8, 0xC9, 0xCA, \
        0xCB, 0xCC, 0xCD, 0xCE, 0xCF, 0xD0, 0xD1, 0xD2, 0xD3, 0xD4, 0xD5, 0xA4, 0xA5, 0xA6, 0xD9, \
        0xDA, 0xDB, 0xDC, 0xA7, 0xA8, 0xDF, 0xA9, 0xAA, 0xAC, 0xAD, 0xB5, 0xB6, 0xB7, 0xB8, 0xBD, \
        0xBE, 0xC6, 0xC7, 0xCF, 0xCF, 0xD0, 0xEF, 0xF0, 0xF1, 0xD1, 0xD2, 0xD3, 0xF5, 0xD4, 0xF7, \
        0xF8, 0xF9, 0xD5, 0x96, 0x95, 0x98, 0xFE, 0xFF                                            \
  }

/* DBCS code range |----- 1st byte -----|  |----------- 2nd byte -----------| */
#define TBL_DC932 \
  { 0x81, 0x9F, 0xE0, 0xFC, 0x40, 0x7E, 0x80, 0xFC, 0x00, 0x00 }
#define TBL_DC936 \
  { 0x81, 0xFE, 0x00, 0x00, 0x40, 0x7E, 0x80, 0xFE, 0x00, 0x00 }
#define TBL_DC949 \
  { 0x81, 0xFE, 0x00, 0x00, 0x41, 0x5A, 0x61, 0x7A, 0x81, 0xFE }
#define TBL_DC950 \
  { 0x81, 0xFE, 0x00, 0x00, 0x40, 0x7E, 0xA1, 0xFE, 0x00, 0x00 }

/* Macros for table definitions */
#define MERGE_2STR(a, b) a##b
#define MKCVTBL(hd, cp) MERGE_2STR(hd, cp)

/*--------------------------------------------------------------------------

   Module Private Work Area

---------------------------------------------------------------------------*/
/* Remark: Variables defined here without initial value shall be guaranteed
/  zero/null at start-up. If not, the linker option or start-up routine is
/  not compliance with C standard. */

/*--------------------------------*/
/* File/Volume controls           */
/*--------------------------------*/

#if FF_VOLUMES < 1 || FF_VOLUMES > 10
#error Wrong FF_VOLUMES setting
#endif
static FATFS* FatFs[FF_VOLUMES]; /* Pointer to the filesystem objects (logical drives) */
static WORD Fsid;                /* File system mount ID */

#if FF_FS_RPATH != 0 && FF_VOLUMES >= 2
static BYTE CurrVol; /* Current drive */
#endif

#if FF_FS_LOCK != 0
static FILESEM Files[FF_FS_LOCK]; /* Open object lock semaphores */
#endif

/*--------------------------------*/
/* LFN/Directory working buffer   */
/*--------------------------------*/

#if FF_USE_LFN == 0 /* Non-LFN configuration */
#define DEF_NAMBUF
#define INIT_NAMBUF(fs)
#define FREE_NAMBUF()

#else /* LFN configurations */
#if FF_MAX_LFN < 12 || FF_MAX_LFN > 255
#error Wrong FF_MAX_LFN setting
#endif
static const BYTE LfnOfs[] = {
    1,  3,  5,  7,  9,  14, 16,
    18, 20, 22, 24, 28, 30};             /* FAT: Offset of LFN characters in the directory entry */
#define MAXDIRB(nc)  \
  ((nc + 44U) / 15 * \
   SZDIRE) /* exFAT: Size of directory entry block scratchpad buffer needed for the max name length */

#if FF_USE_LFN == 1 /* LFN enabled with static working buffer */
#if FF_FS_EXFAT
static BYTE DirBuf[MAXDIRB(FF_MAX_LFN)]; /* Directory entry block scratchpad buffer */
#endif
static WCHAR LfnBuf[FF_MAX_LFN + 1];     /* LFN working buffer */
#define DEF_NAMBUF
#define INIT_NAMBUF(fs)
#define FREE_NAMBUF()

#elif FF_USE_LFN == 2 /* LFN enabled with dynamic working buffer on the stack */
#if FF_FS_EXFAT
#define DEF_NAMBUF            \
  WCHAR lbuf[FF_MAX_LFN + 1]; \
  BYTE dbuf[MAXDIRB(          \
      FF_MAX_LFN)]; /* LFN working buffer and directory entry block scratchpad buffer */
#define INIT_NAMBUF(fs)  \
  {                      \
    (fs)->lfnbuf = lbuf; \
    (fs)->dirbuf = dbuf; \
  }
#define FREE_NAMBUF()
#else
#define DEF_NAMBUF WCHAR lbuf[FF_MAX_LFN + 1]; /* LFN working buffer */
#define INIT_NAMBUF(fs) \
  { (fs)->lfnbuf = lbuf; }
#define FREE_NAMBUF()
#endif

#elif FF_USE_LFN == 3 /* LFN enabled with dynamic working buffer on the heap */
#if FF_FS_EXFAT
#define DEF_NAMBUF \
  WCHAR* lfn; /* Pointer to LFN working buffer and directory entry block scratchpad buffer */
#define INIT_NAMBUF(fs)                                            \
  {                                                                \
    lfn = ff_memalloc((FF_MAX_LFN + 1) * 2 + MAXDIRB(FF_MAX_LFN)); \
    if (!lfn) LEAVE_FF(fs, FR_NOT_ENOUGH_CORE);                    \
    (fs)->lfnbuf = lfn;                                            \
    (fs)->dirbuf = (BYTE*)(lfn + FF_MAX_LFN + 1);                  \
  }
#define FREE_NAMBUF() ff_memfree(lfn)
#else
#define DEF_NAMBUF WCHAR* lfn; /* Pointer to LFN working buffer */
#define INIT_NAMBUF(fs)                         \
  {                                             \
    lfn = ff_memalloc((FF_MAX_LFN + 1) * 2);    \
    if (!lfn) LEAVE_FF(fs, FR_NOT_ENOUGH_CORE); \
    (fs)->lfnbuf = lfn;                         \
  }
#define FREE_NAMBUF() ff_memfree(lfn)
#endif

#else
#error Wrong FF_USE_LFN setting

#endif
#endif

/*--------------------------------*/
/* Code conversion tables         */
/*--------------------------------*/

#if FF_CODE_PAGE == 0 /* Run-time code page configuration */
#define CODEPAGE CodePage
static WORD CodePage; /* Current code page */
static const BYTE *ExCvt,
    *DbcTbl; /* Pointer to current SBCS up-case table and DBCS code range table below */
static const BYTE Ct437[] = TBL_CT437;
static const BYTE Ct720[] = TBL_CT720;
static const BYTE Ct737[] = TBL_CT737;
static const BYTE Ct771[] = TBL_CT771;
static const BYTE Ct775[] = TBL_CT775;
static const BYTE Ct850[] = TBL_CT850;
static const BYTE Ct852[] = TBL_CT852;
static const BYTE Ct855[] = TBL_CT855;
static const BYTE Ct857[] = TBL_CT857;
static const BYTE Ct860[] = TBL_CT860;
static const BYTE Ct861[] = TBL_CT861;
static const BYTE Ct862[] = TBL_CT862;
static const BYTE Ct863[] = TBL_CT863;
static const BYTE Ct864[] = TBL_CT864;
static const BYTE Ct865[] = TBL_CT865;
static const BYTE Ct866[] = TBL_CT866;
static const BYTE Ct869[] = TBL_CT869;
static const BYTE Dc932[] = TBL_DC932;
static const BYTE Dc936[] = TBL_DC936;
static const BYTE Dc949[] = TBL_DC949;
static const BYTE Dc950[] = TBL_DC950;

#elif FF_CODE_PAGE < 900 /* Static code page configuration (SBCS) */
#define CODEPAGE FF_CODE_PAGE
static const BYTE ExCvt[] = MKCVTBL(TBL_CT, FF_CODE_PAGE);

#else /* Static code page configuration (DBCS) */
#define CODEPAGE FF_CODE_PAGE
static const BYTE DbcTbl[] = MKCVTBL(TBL_DC, FF_CODE_PAGE);

#endif

/*--------------------------------------------------------------------------

   Module Private Functions

---------------------------------------------------------------------------*/

/*-----------------------------------------------------------------------*/
/* Load/Store multi-byte word in the FAT structure                       */
/*-----------------------------------------------------------------------*/

static WORD ld_word(const BYTE* ptr) /*	 Load a 2-byte little-endian word */
{
  WORD rv;

  rv = ptr[1];
  rv = rv << 8 | ptr[0];
  return rv;
}

static DWORD ld_dword(const BYTE* ptr) /* Load a 4-byte little-endian word */
{
  DWORD rv;

  rv = ptr[3];
  rv = rv << 8 | ptr[2];
  rv = rv << 8 | ptr[1];
  rv = rv << 8 | ptr[0];
  return rv;
}

#if FF_FS_EXFAT
static QWORD ld_qword(const BYTE* ptr) /* Load an 8-byte little-endian word */
{
  QWORD rv;

  rv = ptr[7];
  rv = rv << 8 | ptr[6];
  rv = rv << 8 | ptr[5];
  rv = rv << 8 | ptr[4];
  rv = rv << 8 | ptr[3];
  rv = rv << 8 | ptr[2];
  rv = rv << 8 | ptr[1];
  rv = rv << 8 | ptr[0];
  return rv;
}
#endif

#if !FF_FS_READONLY
static void st_word(BYTE* ptr, WORD val) /* Store a 2-byte word in little-endian */
{
  *ptr++ = (BYTE)val;
  val >>= 8;
  *ptr++ = (BYTE)val;
}

static void st_dword(BYTE* ptr, DWORD val) /* Store a 4-byte word in little-endian */
{
  *ptr++ = (BYTE)val;
  val >>= 8;
  *ptr++ = (BYTE)val;
  val >>= 8;
  *ptr++ = (BYTE)val;
  val >>= 8;
  *ptr++ = (BYTE)val;
}

#if FF_FS_EXFAT
static void st_qword(BYTE* ptr, QWORD val) /* Store an 8-byte word in little-endian */
{
  *ptr++ = (BYTE)val;
  val >>= 8;
  *ptr++ = (BYTE)val;
  val >>= 8;
  *ptr++ = (BYTE)val;
  val >>= 8;
  *ptr++ = (BYTE)val;
  val >>= 8;
  *ptr++ = (BYTE)val;
  val >>= 8;
  *ptr++ = (BYTE)val;
  val >>= 8;
  *ptr++ = (BYTE)val;
  val >>= 8;
  *ptr++ = (BYTE)val;
}
#endif
#endif /* !FF_FS_READONLY */

/*-----------------------------------------------------------------------*/
/* String functions                                                      */
/*-----------------------------------------------------------------------*/

/* Copy memory to memory */
static void mem_cpy(void* dst, const void* src, UINT cnt) {
  BYTE* d = (BYTE*)dst;
  const BYTE* s = (const BYTE*)src;

  if (cnt != 0) {
    do {
      *d++ = *s++;
    } while (--cnt);
  }
}

/* Fill memory block */
static void mem_set(void* dst, int val, UINT cnt) {
  BYTE* d = (BYTE*)dst;

  do {
    *d++ = (BYTE)val;
  } while (--cnt);
}

/* Compare memory block */
static int mem_cmp(const void* dst, const void* src, UINT cnt) /* ZR:same, NZ:different */
{
  const BYTE *d = (const BYTE*)dst, *s = (const BYTE*)src;
  int r = 0;

  do {
    r = *d++ - *s++;
  } while (--cnt && r == 0);

  return r;
}

/* Check if chr is contained in the string */
static int chk_chr(const char* str, int chr) /* NZ:contained, ZR:not contained */
{
  while (*str && *str != chr) str++;
  return *str;
}

/* Test if the character is DBC 1st byte */
static int dbc_1st(BYTE c) {
#if FF_CODE_PAGE == 0 /* Variable code page */
  if (DbcTbl && c >= DbcTbl[0]) {
    if (c <= DbcTbl[1]) return 1;                   /* 1st byte range 1 */
    if (c >= DbcTbl[2] && c <= DbcTbl[3]) return 1; /* 1st byte range 2 */
  }
#elif FF_CODE_PAGE >= 900 /* DBCS fixed code page */
  if (c >= DbcTbl[0]) {
    if (c <= DbcTbl[1]) return 1;
    if (c >= DbcTbl[2] && c <= DbcTbl[3]) return 1;
  }
#else                     /* SBCS fixed code page */
  if (c) return 0; /* Always false */
#endif
  return 0;
}

/* Test if the character is DBC 2nd byte */
static int dbc_2nd(BYTE c) {
#if FF_CODE_PAGE == 0 /* Variable code page */
  if (DbcTbl && c >= DbcTbl[4]) {
    if (c <= DbcTbl[5]) return 1;                   /* 2nd byte range 1 */
    if (c >= DbcTbl[6] && c <= DbcTbl[7]) return 1; /* 2nd byte range 2 */
    if (c >= DbcTbl[8] && c <= DbcTbl[9]) return 1; /* 2nd byte range 3 */
  }
#elif FF_CODE_PAGE >= 900 /* DBCD fixed code page */
  if (c >= DbcTbl[4]) {
    if (c <= DbcTbl[5]) return 1;
    if (c >= DbcTbl[6] && c <= DbcTbl[7]) return 1;
    if (c >= DbcTbl[8] && c <= DbcTbl[9]) return 1;
  }
#else                     /* SBCS fixed code page */
  if (c) return 0; /* Always false */
#endif
  return 0;
}

#if FF_FS_REENTRANT
/*-----------------------------------------------------------------------*/
/* Request/Release grant to access the volume                            */
/*-----------------------------------------------------------------------*/
static int lock_fs(          /* 1:Ok, 0:timeout */
                   FATFS* fs /* Filesystem object */
) {
  return ff_req_grant(fs->sobj);
}

static void unlock_fs(FATFS* fs,  /* Filesystem object */
                      FRESULT res /* Result code to be returned */
) {
  if (fs && res != FR_NOT_ENABLED && res != FR_INVALID_DRIVE && res != FR_TIMEOUT) {
    ff_rel_grant(fs->sobj);
  }
}

#endif

#if FF_FS_LOCK != 0
/*-----------------------------------------------------------------------*/
/* File lock control functions                                           */
/*-----------------------------------------------------------------------*/

static FRESULT
chk_lock(            /* Check if the file can be accessed */
         FF_DIR* dp, /* Directory object pointing the file to be checked */
         int acc /* Desired access type (0:Read mode open, 1:Write mode open, 2:Delete or rename) */
) {
  UINT i, be;

  /* Search open object table for the object */
  be = 0;
  for (i = 0; i < FF_FS_LOCK; i++) {
    if (Files[i].fs) {                 /* Existing entry */
      if (Files[i].fs == dp->obj.fs && /* Check if the object matches with an open object */
          Files[i].clu == dp->obj.sclust && Files[i].ofs == dp->dptr)
        break;
    } else { /* Blank entry */
      be = 1;
    }
  }
  if (i == FF_FS_LOCK) { /* The object has not been opened */
    return (!be && acc != 2) ? FR_TOO_MANY_OPEN_FILES
                             : FR_OK; /* Is there a blank entry for new object? */
  }

  /* The object was opened. Reject any open against writing file and all write mode open */
  return (acc != 0 || Files[i].ctr == 0x100) ? FR_LOCKED : FR_OK;
}

static int enq_lock(void) /* Check if an entry is available for a new object */
{
  UINT i;

  for (i = 0; i < FF_FS_LOCK && Files[i].fs; i++)
    ;
  return (i == FF_FS_LOCK) ? 0 : 1;
}

static UINT inc_lock(/* Increment object open counter and returns its index (0:Internal error) */
                     FF_DIR* dp, /* Directory object pointing the file to register or increment */
                     int acc     /* Desired access (0:Read, 1:Write, 2:Delete/Rename) */
) {
  UINT i;

  for (i = 0; i < FF_FS_LOCK; i++) { /* Find the object */
    if (Files[i].fs == dp->obj.fs && Files[i].clu == dp->obj.sclust && Files[i].ofs == dp->dptr)
      break;
  }

  if (i == FF_FS_LOCK) { /* Not opened. Register it as new. */
    for (i = 0; i < FF_FS_LOCK && Files[i].fs; i++)
      ;
    if (i == FF_FS_LOCK) return 0; /* No free entry to register (int err) */
    Files[i].fs = dp->obj.fs;
    Files[i].clu = dp->obj.sclust;
    Files[i].ofs = dp->dptr;
    Files[i].ctr = 0;
  }

  if (acc && Files[i].ctr) return 0; /* Access violation (int err) */

  Files[i].ctr = acc ? 0x100 : Files[i].ctr + 1; /* Set semaphore value */

  return i + 1; /* Index number origin from 1 */
}

static FRESULT dec_lock(       /* Decrement object open counter */
                        UINT i /* Semaphore index (1..) */
) {
  WORD n;
  FRESULT res;

  if (--i < FF_FS_LOCK) { /* Index number origin from 0 */
    n = Files[i].ctr;
    if (n == 0x100) n = 0; /* If write mode open, delete the entry */
    if (n > 0) n--;        /* Decrement read mode open count */
    Files[i].ctr = n;
    if (n == 0) Files[i].fs = 0; /* Delete the entry if open count gets zero */
    res = FR_OK;
  } else {
    res = FR_INT_ERR; /* Invalid index nunber */
  }
  return res;
}

static void clear_lock(/* Clear lock entries of the volume */
                       FATFS* fs) {
  UINT i;

  for (i = 0; i < FF_FS_LOCK; i++) {
    if (Files[i].fs == fs) Files[i].fs = 0;
  }
}

#endif /* FF_FS_LOCK != 0 */

/*-----------------------------------------------------------------------*/
/* Move/Flush disk access window in the filesystem object                */
/*-----------------------------------------------------------------------*/
#if !FF_FS_READONLY
static FRESULT sync_window(          /* Returns FR_OK or FR_DISK_ERR */
                           FATFS* fs /* Filesystem object */
) {
  FRESULT res = FR_OK;

  if (fs->wflag) { /* Is the disk access window dirty */
    if (disk_write(fs->pdrv, fs->win, fs->winsect, 1) == RES_OK) { /* Write back the window */
      fs->wflag = 0;                                               /* Clear window dirty flag */
      if (fs->winsect - fs->fatbase < fs->fsize) {                 /* Is it in the 1st FAT? */
        if (fs->n_fats == 2)
          disk_write(fs->pdrv, fs->win, fs->winsect + fs->fsize,
                     1); /* Reflect it to 2nd FAT if needed */
      }
    } else {
      res = FR_DISK_ERR;
    }
  }
  return res;
}
#endif

static FRESULT move_window(             /* Returns FR_OK or FR_DISK_ERR */
                           FATFS* fs,   /* Filesystem object */
                           DWORD sector /* Sector number to make appearance in the fs->win[] */
) {
  FRESULT res = FR_OK;

  if (sector != fs->winsect) { /* Window offset changed? */
#if !FF_FS_READONLY
    res = sync_window(fs); /* Write-back changes */
#endif
    if (res == FR_OK) { /* Fill sector window with new data */
      if (disk_read(fs->pdrv, fs->win, sector, 1) != RES_OK) {
        sector = 0xFFFFFFFF; /* Invalidate window if read data is not valid */
        res = FR_DISK_ERR;
      }
      fs->winsect = sector;
    }
  }
  return res;
}

#if !FF_FS_READONLY
/*-----------------------------------------------------------------------*/
/* Synchronize filesystem and data on the storage                        */
/*-----------------------------------------------------------------------*/

static FRESULT sync_fs(          /* Returns FR_OK or FR_DISK_ERR */
                       FATFS* fs /* Filesystem object */
) {
  FRESULT res;

  res = sync_window(fs);
  if (res == FR_OK) {
    if (fs->fs_type == FS_FAT32 && fs->fsi_flag == 1) { /* FAT32: Update FSInfo sector if needed */
      /* Create FSInfo structure */
      mem_set(fs->win, 0, SS(fs));
      st_word(fs->win + BS_55AA, 0xAA55);
      st_dword(fs->win + FSI_LeadSig, 0x41615252);
      st_dword(fs->win + FSI_StrucSig, 0x61417272);
      st_dword(fs->win + FSI_Free_Count, fs->free_clst);
      st_dword(fs->win + FSI_Nxt_Free, fs->last_clst);
      /* Write it into the FSInfo sector */
      fs->winsect = fs->volbase + 1;
      disk_write(fs->pdrv, fs->win, fs->winsect, 1);
      fs->fsi_flag = 0;
    }
    /* Make sure that no pending write process in the lower layer */
    if (disk_ioctl(fs->pdrv, CTRL_SYNC, 0) != RES_OK) res = FR_DISK_ERR;
  }

  return res;
}

#endif

/*-----------------------------------------------------------------------*/
/* Get physical sector number from cluster number                        */
/*-----------------------------------------------------------------------*/

static DWORD clst2sect(           /* !=0:Sector number, 0:Failed (invalid cluster#) */
                       FATFS* fs, /* Filesystem object */
                       DWORD clst /* Cluster# to be converted */
) {
  clst -= 2;                              /* Cluster number is origin from 2 */
  if (clst >= fs->n_fatent - 2) return 0; /* Is it invalid cluster number? */
  return fs->database + fs->csize * clst; /* Start sector number of the cluster */
}

/*-----------------------------------------------------------------------*/
/* FAT access - Read value of a FAT entry                                */
/*-----------------------------------------------------------------------*/

static DWORD get_fat(/* 0xFFFFFFFF:Disk error, 1:Internal error, 2..0x7FFFFFFF:Cluster status */
                     FFOBJID* obj, /* Corresponding object */
                     DWORD clst    /* Cluster number to get the value */
) {
  UINT wc, bc;
  DWORD val;
  FATFS* fs = obj->fs;

  if (clst < 2 || clst >= fs->n_fatent) { /* Check if in valid range */
    val = 1;                              /* Internal error */

  } else {
    val = 0xFFFFFFFF; /* Default value falls on disk error */

    switch (fs->fs_type) {
      case FS_FAT12:
        bc = (UINT)clst;
        bc += bc / 2;
        if (move_window(fs, fs->fatbase + (bc / SS(fs))) != FR_OK) break;
        wc = fs->win[bc++ % SS(fs)]; /* Get 1st byte of the entry */
        if (move_window(fs, fs->fatbase + (bc / SS(fs))) != FR_OK) break;
        wc |= fs->win[bc % SS(fs)] << 8;             /* Merge 2nd byte of the entry */
        val = (clst & 1) ? (wc >> 4) : (wc & 0xFFF); /* Adjust bit position */
        break;

      case FS_FAT16:
        if (move_window(fs, fs->fatbase + (clst / (SS(fs) / 2))) != FR_OK) break;
        val = ld_word(fs->win + clst * 2 % SS(fs)); /* Simple WORD array */
        break;

      case FS_FAT32:
        if (move_window(fs, fs->fatbase + (clst / (SS(fs) / 4))) != FR_OK) break;
        val = ld_dword(fs->win + clst * 4 % SS(fs)) &
              0x0FFFFFFF; /* Simple DWORD array but mask out upper 4 bits */
        break;
#if FF_FS_EXFAT
      case FS_EXFAT:
        if (obj->objsize != 0) {
          DWORD cofs = clst - obj->sclust; /* Offset from start cluster */
          DWORD clen =
              (DWORD)((obj->objsize - 1) / SS(fs)) / fs->csize; /* Number of clusters - 1 */

          if (obj->stat == 2 && cofs <= clen) { /* Is it a contiguous chain? */
            val =
                (cofs == clen) ? 0x7FFFFFFF : clst + 1; /* No data on the FAT, generate the value */
            break;
          }
          if (obj->stat == 3 && cofs < obj->n_cont) { /* Is it in the 1st fragment? */
            val = clst + 1;                           /* Generate the value */
            break;
          }
          if (obj->stat != 2) {     /* Get value from FAT if FAT chain is valid */
            if (obj->n_frag != 0) { /* Is it on the growing edge? */
              val = 0x7FFFFFFF;     /* Generate EOC */
            } else {
              if (move_window(fs, fs->fatbase + (clst / (SS(fs) / 4))) != FR_OK) break;
              val = ld_dword(fs->win + clst * 4 % SS(fs)) & 0x7FFFFFFF;
            }
            break;
          }
        }
        /* go to default */
#endif
      default:
        val = 1; /* Internal error */
    }
  }

  return val;
}

#if !FF_FS_READONLY
/*-----------------------------------------------------------------------*/
/* FAT access - Change value of a FAT entry                              */
/*-----------------------------------------------------------------------*/

static FRESULT put_fat(            /* FR_OK(0):succeeded, !=0:error */
                       FATFS* fs,  /* Corresponding filesystem object */
                       DWORD clst, /* FAT index number (cluster number) to be changed */
                       DWORD val   /* New value to be set to the entry */
) {
  UINT bc;
  BYTE* p;
  FRESULT res = FR_INT_ERR;

  if (clst >= 2 && clst < fs->n_fatent) { /* Check if in valid range */
    switch (fs->fs_type) {
      case FS_FAT12:
        bc = (UINT)clst;
        bc += bc / 2; /* bc: byte offset of the entry */
        res = move_window(fs, fs->fatbase + (bc / SS(fs)));
        if (res != FR_OK) break;
        p = fs->win + bc++ % SS(fs);
        *p = (clst & 1) ? ((*p & 0x0F) | ((BYTE)val << 4)) : (BYTE)val; /* Put 1st byte */
        fs->wflag = 1;
        res = move_window(fs, fs->fatbase + (bc / SS(fs)));
        if (res != FR_OK) break;
        p = fs->win + bc % SS(fs);
        *p = (clst & 1) ? (BYTE)(val >> 4)
                        : ((*p & 0xF0) | ((BYTE)(val >> 8) & 0x0F)); /* Put 2nd byte */
        fs->wflag = 1;
        break;

      case FS_FAT16:
        res = move_window(fs, fs->fatbase + (clst / (SS(fs) / 2)));
        if (res != FR_OK) break;
        st_word(fs->win + clst * 2 % SS(fs), (WORD)val); /* Simple WORD array */
        fs->wflag = 1;
        break;

      case FS_FAT32:
#if FF_FS_EXFAT
      case FS_EXFAT:
#endif
        res = move_window(fs, fs->fatbase + (clst / (SS(fs) / 4)));
        if (res != FR_OK) break;
        if (!FF_FS_EXFAT || fs->fs_type != FS_EXFAT) {
          val = (val & 0x0FFFFFFF) | (ld_dword(fs->win + clst * 4 % SS(fs)) & 0xF0000000);
        }
        st_dword(fs->win + clst * 4 % SS(fs), val);
        fs->wflag = 1;
        break;
    }
  }
  return res;
}

#endif /* !FF_FS_READONLY */

#if FF_FS_EXFAT && !FF_FS_READONLY
/*-----------------------------------------------------------------------*/
/* exFAT: Accessing FAT and Allocation Bitmap                            */
/*-----------------------------------------------------------------------*/

/*--------------------------------------*/
/* Find a contiguous free cluster block */
/*--------------------------------------*/

static DWORD find_bitmap(/* 0:Not found, 2..:Cluster block found, 0xFFFFFFFF:Disk error */
                         FATFS* fs,  /* Filesystem object */
                         DWORD clst, /* Cluster number to scan from */
                         DWORD ncl   /* Number of contiguous clusters to find (1..) */
) {
  BYTE bm, bv;
  UINT i;
  DWORD val, scl, ctr;

  clst -= 2; /* The first bit in the bitmap corresponds to cluster #2 */
  if (clst >= fs->n_fatent - 2) clst = 0;
  scl = val = clst;
  ctr = 0;
  for (;;) {
    if (move_window(fs, fs->database + val / 8 / SS(fs)) != FR_OK)
      return 0xFFFFFFFF; /* (assuming bitmap is located top of the cluster heap) */
    i = val / 8 % SS(fs);
    bm = 1 << (val % 8);
    do {
      do {
        bv = fs->win[i] & bm;
        bm <<= 1;                        /* Get bit value */
        if (++val >= fs->n_fatent - 2) { /* Next cluster (with wrap-around) */
          val = 0;
          bm = 0;
          i = SS(fs);
        }
        if (!bv) {                          /* Is it a free cluster? */
          if (++ctr == ncl) return scl + 2; /* Check if run length is sufficient for required */
        } else {
          scl = val;
          ctr = 0; /* Encountered a cluster in-use, restart to scan */
        }
        if (val == clst) return 0; /* All cluster scanned? */
      } while (bm);
      bm = 1;
    } while (++i < SS(fs));
  }
}

/*----------------------------------------*/
/* Set/Clear a block of allocation bitmap */
/*----------------------------------------*/

static FRESULT change_bitmap(FATFS* fs,  /* Filesystem object */
                             DWORD clst, /* Cluster number to change from */
                             DWORD ncl,  /* Number of clusters to be changed */
                             int bv      /* bit value to be set (0 or 1) */
) {
  BYTE bm;
  UINT i;
  DWORD sect;

  clst -= 2; /* The first bit corresponds to cluster #2 */
  sect =
      fs->database +
      clst / 8 / SS(fs); /* Sector address (assuming bitmap is located top of the cluster heap) */
  i = clst / 8 % SS(fs); /* Byte offset in the sector */
  bm = 1 << (clst % 8);  /* Bit mask in the byte */
  for (;;) {
    if (move_window(fs, sect++) != FR_OK) return FR_DISK_ERR;
    do {
      do {
        if (bv == (int)((fs->win[i] & bm) != 0)) return FR_INT_ERR; /* Is the bit expected value? */
        fs->win[i] ^= bm;                                           /* Flip the bit */
        fs->wflag = 1;
        if (--ncl == 0) return FR_OK; /* All bits processed? */
      } while (bm <<= 1);             /* Next bit */
      bm = 1;
    } while (++i < SS(fs)); /* Next byte */
    i = 0;
  }
}

/*---------------------------------------------*/
/* Fill the first fragment of the FAT chain    */
/*---------------------------------------------*/

static FRESULT fill_first_frag(FFOBJID* obj /* Pointer to the corresponding object */
) {
  FRESULT res;
  DWORD cl, n;

  if (obj->stat == 3) { /* Has the object been changed 'fragmented' in this session? */
    for (cl = obj->sclust, n = obj->n_cont; n; cl++, n--) { /* Create cluster chain on the FAT */
      res = put_fat(obj->fs, cl, cl + 1);
      if (res != FR_OK) return res;
    }
    obj->stat = 0; /* Change status 'FAT chain is valid' */
  }
  return FR_OK;
}

/*---------------------------------------------*/
/* Fill the last fragment of the FAT chain     */
/*---------------------------------------------*/

static FRESULT fill_last_frag(FFOBJID* obj, /* Pointer to the corresponding object */
                              DWORD lcl,    /* Last cluster of the fragment */
                              DWORD term    /* Value to set the last FAT entry */
) {
  FRESULT res;

  while (obj->n_frag > 0) { /* Create the last chain on the FAT */
    res = put_fat(obj->fs, lcl - obj->n_frag + 1, (obj->n_frag > 1) ? lcl - obj->n_frag + 2 : term);
    if (res != FR_OK) return res;
    obj->n_frag--;
  }
  return FR_OK;
}

#endif /* FF_FS_EXFAT && !FF_FS_READONLY */

#if !FF_FS_READONLY
/*-----------------------------------------------------------------------*/
/* FAT handling - Remove a cluster chain                                 */
/*-----------------------------------------------------------------------*/
static FRESULT remove_chain(              /* FR_OK(0):succeeded, !=0:error */
                            FFOBJID* obj, /* Corresponding object */
                            DWORD clst,   /* Cluster to remove a chain from */
                            DWORD pclst   /* Previous cluster of clst (0:entire chain) */
) {
  FRESULT res = FR_OK;
  DWORD nxt;
  FATFS* fs = obj->fs;
#if FF_FS_EXFAT || FF_USE_TRIM
  DWORD scl = clst, ecl = clst;
#endif
#if FF_USE_TRIM
  DWORD rt[2];
#endif

  if (clst < 2 || clst >= fs->n_fatent) return FR_INT_ERR; /* Check if in valid range */

  /* Mark the previous cluster 'EOC' on the FAT if it exists */
  if (pclst != 0 && (!FF_FS_EXFAT || fs->fs_type != FS_EXFAT || obj->stat != 2)) {
    res = put_fat(fs, pclst, 0xFFFFFFFF);
    if (res != FR_OK) return res;
  }

  /* Remove the chain */
  do {
    nxt = get_fat(obj, clst);                  /* Get cluster status */
    if (nxt == 0) break;                       /* Empty cluster? */
    if (nxt == 1) return FR_INT_ERR;           /* Internal error? */
    if (nxt == 0xFFFFFFFF) return FR_DISK_ERR; /* Disk error? */
    if (!FF_FS_EXFAT || fs->fs_type != FS_EXFAT) {
      res = put_fat(fs, clst, 0); /* Mark the cluster 'free' on the FAT */
      if (res != FR_OK) return res;
    }
    if (fs->free_clst < fs->n_fatent - 2) { /* Update FSINFO */
      fs->free_clst++;
      fs->fsi_flag |= 1;
    }
#if FF_FS_EXFAT || FF_USE_TRIM
    if (ecl + 1 == nxt) { /* Is next cluster contiguous? */
      ecl = nxt;
    } else { /* End of contiguous cluster block */
#if FF_FS_EXFAT
      if (fs->fs_type == FS_EXFAT) {
        res = change_bitmap(fs, scl, ecl - scl + 1,
                            0); /* Mark the cluster block 'free' on the bitmap */
        if (res != FR_OK) return res;
      }
#endif
#if FF_USE_TRIM
      rt[0] = clst2sect(fs, scl);                 /* Start of data area freed */
      rt[1] = clst2sect(fs, ecl) + fs->csize - 1; /* End of data area freed */
      disk_ioctl(fs->pdrv, CTRL_TRIM,
                 rt); /* Inform device the data in the block is no longer needed */
#endif
      scl = ecl = nxt;
    }
#endif
    clst = nxt;                  /* Next cluster */
  } while (clst < fs->n_fatent); /* Repeat while not the last link */

#if FF_FS_EXFAT
  /* Some post processes for chain status */
  if (fs->fs_type == FS_EXFAT) {
    if (pclst == 0) { /* Has the entire chain been removed? */
      obj->stat = 0;  /* Change the chain status 'initial' */
    } else {
      if (obj->stat == 0) { /* Is it a fragmented chain from the beginning of this session? */
        clst = obj->sclust; /* Follow the chain to check if it gets contiguous */
        while (clst != pclst) {
          nxt = get_fat(obj, clst);
          if (nxt < 2) return FR_INT_ERR;
          if (nxt == 0xFFFFFFFF) return FR_DISK_ERR;
          if (nxt != clst + 1) break; /* Not contiguous? */
          clst++;
        }
        if (clst == pclst) { /* Has the chain got contiguous again? */
          obj->stat = 2;     /* Change the chain status 'contiguous' */
        }
      } else {
        if (obj->stat == 3 && pclst >= obj->sclust &&
            pclst <=
                obj->sclust +
                    obj->n_cont) { /* Was the chain fragmented in this session and got contiguous again? */
          obj->stat = 2;           /* Change the chain status 'contiguous' */
        }
      }
    }
  }
#endif
  return FR_OK;
}

/*-----------------------------------------------------------------------*/
/* FAT handling - Stretch a chain or Create a new chain                  */
/*-----------------------------------------------------------------------*/
static DWORD
create_chain(/* 0:No free cluster, 1:Internal error, 0xFFFFFFFF:Disk error, >=2:New cluster# */
             FFOBJID* obj, /* Corresponding object */
             DWORD clst    /* Cluster# to stretch, 0:Create a new chain */
) {
  DWORD cs, ncl, scl;
  FRESULT res;
  FATFS* fs = obj->fs;

  if (clst == 0) {       /* Create a new chain */
    scl = fs->last_clst; /* Suggested cluster to start to find */
    if (scl == 0 || scl >= fs->n_fatent) scl = 1;
  } else {                            /* Stretch a chain */
    cs = get_fat(obj, clst);          /* Check the cluster status */
    if (cs < 2) return 1;             /* Test for insanity */
    if (cs == 0xFFFFFFFF) return cs;  /* Test for disk error */
    if (cs < fs->n_fatent) return cs; /* It is already followed by next cluster */
    scl = clst;                       /* Cluster to start to find */
  }
  if (fs->free_clst == 0) return 0; /* No free cluster */

#if FF_FS_EXFAT
  if (fs->fs_type == FS_EXFAT) {                   /* On the exFAT volume */
    ncl = find_bitmap(fs, scl, 1);                 /* Find a free cluster */
    if (ncl == 0 || ncl == 0xFFFFFFFF) return ncl; /* No free cluster or hard error? */
    res = change_bitmap(fs, ncl, 1, 1);            /* Mark the cluster 'in use' */
    if (res == FR_INT_ERR) return 1;
    if (res == FR_DISK_ERR) return 0xFFFFFFFF;
    if (clst == 0) {                          /* Is it a new chain? */
      obj->stat = 2;                          /* Set status 'contiguous' */
    } else {                                  /* It is a stretched chain */
      if (obj->stat == 2 && ncl != scl + 1) { /* Is the chain got fragmented? */
        obj->n_cont = scl - obj->sclust;      /* Set size of the contiguous part */
        obj->stat = 3;                        /* Change status 'just fragmented' */
      }
    }
    if (obj->stat != 2) {                                /* Is the file non-contiguous? */
      if (ncl == clst + 1) {                             /* Is the cluster next to previous one? */
        obj->n_frag = obj->n_frag ? obj->n_frag + 1 : 2; /* Increment size of last framgent */
      } else {                                           /* New fragment */
        if (obj->n_frag == 0) obj->n_frag = 1;
        res = fill_last_frag(obj, clst,
                             ncl); /* Fill last fragment on the FAT and link it to new one */
        if (res == FR_OK) obj->n_frag = 1;
      }
    }
  } else
#endif
  { /* On the FAT/FAT32 volume */
    ncl = 0;
    if (scl == clst) { /* Stretching an existing chain? */
      ncl = scl + 1;   /* Test if next cluster is free */
      if (ncl >= fs->n_fatent) ncl = 2;
      cs = get_fat(obj, ncl);                     /* Get next cluster status */
      if (cs == 1 || cs == 0xFFFFFFFF) return cs; /* Test for error */
      if (cs != 0) {                              /* Not free? */
        cs = fs->last_clst;                       /* Start at suggested cluster if it is valid */
        if (cs >= 2 && cs < fs->n_fatent) scl = cs;
        ncl = 0;
      }
    }
    if (ncl == 0) { /* The new cluster cannot be contiguous and find another fragment */
      ncl = scl;    /* Start cluster */
      for (;;) {
        ncl++;                     /* Next cluster */
        if (ncl >= fs->n_fatent) { /* Check wrap-around */
          ncl = 2;
          if (ncl > scl) return 0; /* No free cluster found? */
        }
        cs = get_fat(obj, ncl);                     /* Get the cluster status */
        if (cs == 0) break;                         /* Found a free cluster? */
        if (cs == 1 || cs == 0xFFFFFFFF) return cs; /* Test for error */
        if (ncl == scl) return 0;                   /* No free cluster found? */
      }
    }
    res = put_fat(fs, ncl, 0xFFFFFFFF); /* Mark the new cluster 'EOC' */
    if (res == FR_OK && clst != 0) {
      res = put_fat(fs, clst, ncl); /* Link it from the previous one if needed */
    }
  }

  if (res == FR_OK) { /* Update FSINFO if function succeeded. */
    fs->last_clst = ncl;
    if (fs->free_clst <= fs->n_fatent - 2) fs->free_clst--;
    fs->fsi_flag |= 1;
  } else {
    ncl = (res == FR_DISK_ERR) ? 0xFFFFFFFF : 1; /* Failed. Generate error status */
  }

  return ncl; /* Return new cluster number or error status */
}

#endif /* !FF_FS_READONLY */

#if FF_USE_FASTSEEK
/*-----------------------------------------------------------------------*/
/* FAT handling - Convert offset into cluster with link map table        */
/*-----------------------------------------------------------------------*/

static DWORD clmt_clust(            /* <2:Error, >=2:Cluster number */
                        FIL* fp,    /* Pointer to the file object */
                        FSIZE_t ofs /* File offset to be converted to cluster# */
) {
  DWORD cl, ncl, *tbl;
  FATFS* fs = fp->obj.fs;

  tbl = fp->cltbl + 1;                    /* Top of CLMT */
  cl = (DWORD)(ofs / SS(fs) / fs->csize); /* Cluster order from top of the file */
  for (;;) {
    ncl = *tbl++;           /* Number of cluters in the fragment */
    if (ncl == 0) return 0; /* End of table? (error) */
    if (cl < ncl) break;    /* In this fragment? */
    cl -= ncl;
    tbl++; /* Next fragment */
  }
  return cl + *tbl; /* Return the cluster number */
}

#endif /* FF_USE_FASTSEEK */

/*-----------------------------------------------------------------------*/
/* Directory handling - Fill a cluster with zeros                        */
/*-----------------------------------------------------------------------*/

#if !FF_FS_READONLY
static FRESULT dir_clear(           /* Returns FR_OK or FR_DISK_ERR */
                         FATFS* fs, /* Filesystem object */
                         DWORD clst /* Directory table to clear */
) {
  DWORD sect;
  UINT n, szb;
  BYTE* ibuf;

  if (sync_window(fs) != FR_OK) return FR_DISK_ERR; /* Flush disk access window */
  sect = clst2sect(fs, clst);                       /* Top of the cluster */
  fs->winsect = sect;                               /* Set window to top of the cluster */
  mem_set(fs->win, 0, SS(fs));                      /* Clear window buffer */
#if FF_USE_LFN == 3 /* Quick table clear by using multi-secter write */
  /* Allocate a temporary buffer (32 KB max) */
  for (szb = ((DWORD)fs->csize * SS(fs) >= 0x8000) ? 0x8000 : fs->csize * SS(fs);
       szb > SS(fs) && !(ibuf = ff_memalloc(szb)); szb /= 2)
    ;
  if (szb > SS(fs)) { /* Buffer allocated? */
    mem_set(ibuf, 0, szb);
    szb /= SS(fs); /* Bytes -> Sectors */
    for (n = 0; n < fs->csize && disk_write(fs->pdrv, ibuf, sect + n, szb) == RES_OK; n += szb)
      ; /* Fill the cluster with 0 */
    ff_memfree(ibuf);
  } else
#endif
  {
    ibuf = fs->win;
    szb = 1; /* Use window buffer (single-sector writes may take a time) */
    for (n = 0; n < fs->csize && disk_write(fs->pdrv, ibuf, sect + n, szb) == RES_OK; n += szb)
      ; /* Fill the cluster with 0 */
  }
  return (n == fs->csize) ? FR_OK : FR_DISK_ERR;
}
#endif /* !FF_FS_READONLY */

/*-----------------------------------------------------------------------*/
/* Directory handling - Set directory index                              */
/*-----------------------------------------------------------------------*/

static FRESULT dir_sdi(            /* FR_OK(0):succeeded, !=0:error */
                       FF_DIR* dp, /* Pointer to directory object */
                       DWORD ofs   /* Offset of directory table */
) {
  DWORD csz, clst;
  FATFS* fs = dp->obj.fs;

  if (ofs >= (DWORD)((FF_FS_EXFAT && fs->fs_type == FS_EXFAT) ? MAX_DIR_EX : MAX_DIR) ||
      ofs % SZDIRE) { /* Check range of offset and alignment */
    return FR_INT_ERR;
  }
  dp->dptr = ofs;                             /* Set current offset */
  clst = dp->obj.sclust;                      /* Table start cluster (0:root) */
  if (clst == 0 && fs->fs_type >= FS_FAT32) { /* Replace cluster# 0 with root cluster# */
    clst = fs->dirbase;
    if (FF_FS_EXFAT) dp->obj.stat = 0; /* exFAT: Root dir has an FAT chain */
  }

  if (clst == 0) { /* Static table (root-directory on the FAT volume) */
    if (ofs / SZDIRE >= fs->n_rootdir) return FR_INT_ERR; /* Is index out of range? */
    dp->sect = fs->dirbase;

  } else { /* Dynamic table (sub-directory or root-directory on the FAT32/exFAT volume) */
    csz = (DWORD)fs->csize * SS(fs);              /* Bytes per cluster */
    while (ofs >= csz) {                          /* Follow cluster chain */
      clst = get_fat(&dp->obj, clst);             /* Get next cluster */
      if (clst == 0xFFFFFFFF) return FR_DISK_ERR; /* Disk error */
      if (clst < 2 || clst >= fs->n_fatent)
        return FR_INT_ERR; /* Reached to end of table or internal error */
      ofs -= csz;
    }
    dp->sect = clst2sect(fs, clst);
  }
  dp->clust = clst; /* Current cluster# */
  if (dp->sect == 0) return FR_INT_ERR;
  dp->sect += ofs / SS(fs);           /* Sector# of the directory entry */
  dp->dir = fs->win + (ofs % SS(fs)); /* Pointer to the entry in the win[] */

  return FR_OK;
}

/*-----------------------------------------------------------------------*/
/* Directory handling - Move directory table index next                  */
/*-----------------------------------------------------------------------*/

static FRESULT
dir_next(            /* FR_OK(0):succeeded, FR_NO_FILE:End of table, FR_DENIED:Could not stretch */
         FF_DIR* dp, /* Pointer to the directory object */
         int stretch /* 0: Do not stretch table, 1: Stretch table if needed */
) {
  DWORD ofs, clst;
  FATFS* fs = dp->obj.fs;

  ofs = dp->dptr + SZDIRE; /* Next entry */
  if (dp->sect == 0 ||
      ofs >= (DWORD)((FF_FS_EXFAT && fs->fs_type == FS_EXFAT) ? MAX_DIR_EX : MAX_DIR))
    return FR_NO_FILE; /* Report EOT when offset has reached max value */

  if (ofs % SS(fs) == 0) { /* Sector changed? */
    dp->sect++;            /* Next sector */

    if (dp->clust == 0) {                  /* Static table */
      if (ofs / SZDIRE >= fs->n_rootdir) { /* Report EOT if it reached end of static table */
        dp->sect = 0;
        return FR_NO_FILE;
      }
    } else {                                        /* Dynamic table */
      if ((ofs / SS(fs) & (fs->csize - 1)) == 0) {  /* Cluster changed? */
        clst = get_fat(&dp->obj, dp->clust);        /* Get next cluster */
        if (clst <= 1) return FR_INT_ERR;           /* Internal error */
        if (clst == 0xFFFFFFFF) return FR_DISK_ERR; /* Disk error */
        if (clst >= fs->n_fatent) {                 /* It reached end of dynamic table */
#if !FF_FS_READONLY
          if (!stretch) { /* If no stretch, report EOT */
            dp->sect = 0;
            return FR_NO_FILE;
          }
          clst = create_chain(&dp->obj, dp->clust);             /* Allocate a cluster */
          if (clst == 0) return FR_DENIED;                      /* No free cluster */
          if (clst == 1) return FR_INT_ERR;                     /* Internal error */
          if (clst == 0xFFFFFFFF) return FR_DISK_ERR;           /* Disk error */
          if (dir_clear(fs, clst) != FR_OK) return FR_DISK_ERR; /* Clean up the stretched table */
          if (FF_FS_EXFAT) dp->obj.stat |= 4; /* exFAT: The directory has been stretched */
#else
          if (!stretch) dp->sect = 0; /* (this line is to suppress compiler warning) */
          dp->sect = 0;
          return FR_NO_FILE; /* Report EOT */
#endif
        }
        dp->clust = clst; /* Initialize data for new cluster */
        dp->sect = clst2sect(fs, clst);
      }
    }
  }
  dp->dptr = ofs;                   /* Current entry */
  dp->dir = fs->win + ofs % SS(fs); /* Pointer to the entry in the win[] */

  return FR_OK;
}

#if !FF_FS_READONLY
/*-----------------------------------------------------------------------*/
/* Directory handling - Reserve a block of directory entries             */
/*-----------------------------------------------------------------------*/

static FRESULT dir_alloc(            /* FR_OK(0):succeeded, !=0:error */
                         FF_DIR* dp, /* Pointer to the directory object */
                         UINT nent   /* Number of contiguous entries to allocate */
) {
  FRESULT res;
  UINT n;
  FATFS* fs = dp->obj.fs;

  res = dir_sdi(dp, 0);
  if (res == FR_OK) {
    n = 0;
    do {
      res = move_window(fs, dp->sect);
      if (res != FR_OK) break;
#if FF_FS_EXFAT
      if ((fs->fs_type == FS_EXFAT) ? (int)((dp->dir[XDIR_Type] & 0x80) == 0)
                                    : (int)(dp->dir[DIR_Name] == DDEM || dp->dir[DIR_Name] == 0)) {
#else
      if (dp->dir[DIR_Name] == DDEM || dp->dir[DIR_Name] == 0) {
#endif
        if (++n == nent) break; /* A block of contiguous free entries is found */
      } else {
        n = 0; /* Not a blank entry. Restart to search */
      }
      res = dir_next(dp, 1);
    } while (res == FR_OK); /* Next entry with table stretch enabled */
  }

  if (res == FR_NO_FILE) res = FR_DENIED; /* No directory entry to allocate */
  return res;
}

#endif /* !FF_FS_READONLY */

/*-----------------------------------------------------------------------*/
/* FAT: Directory handling - Load/Store start cluster number             */
/*-----------------------------------------------------------------------*/

static DWORD ld_clust(                /* Returns the top cluster value of the SFN entry */
                      FATFS* fs,      /* Pointer to the fs object */
                      const BYTE* dir /* Pointer to the key entry */
) {
  DWORD cl;

  cl = ld_word(dir + DIR_FstClusLO);
  if (fs->fs_type == FS_FAT32) {
    cl |= (DWORD)ld_word(dir + DIR_FstClusHI) << 16;
  }

  return cl;
}

#if !FF_FS_READONLY
static void st_clust(FATFS* fs, /* Pointer to the fs object */
                     BYTE* dir, /* Pointer to the key entry */
                     DWORD cl   /* Value to be set */
) {
  st_word(dir + DIR_FstClusLO, (WORD)cl);
  if (fs->fs_type == FS_FAT32) {
    st_word(dir + DIR_FstClusHI, (WORD)(cl >> 16));
  }
}
#endif

#if FF_USE_LFN
/*--------------------------------------------------------*/
/* FAT-LFN: Compare a part of file name with an LFN entry */
/*--------------------------------------------------------*/
static int cmp_lfn(                     /* 1:matched, 0:not matched */
                   const WCHAR* lfnbuf, /* Pointer to the LFN working buffer to be compared */
                   BYTE* dir /* Pointer to the directory entry containing the part of LFN */
) {
  UINT i, s;
  WCHAR wc, uc;

  if (ld_word(dir + LDIR_FstClusLO) != 0) return 0; /* Check LDIR_FstClusLO */

  i = ((dir[LDIR_Ord] & 0x3F) - 1) * 13; /* Offset in the LFN buffer */

  for (wc = 1, s = 0; s < 13; s++) { /* Process all characters in the entry */
    uc = ld_word(dir + LfnOfs[s]);   /* Pick an LFN character */
    if (wc) {
      if (i >= FF_MAX_LFN || ff_wtoupper(uc) != ff_wtoupper(lfnbuf[i++])) { /* Compare it */
        return 0;                                                           /* Not matched */
      }
      wc = uc;
    } else {
      if (uc != 0xFFFF) return 0; /* Check filler */
    }
  }

  if ((dir[LDIR_Ord] & LLEF) && wc && lfnbuf[i])
    return 0; /* Last segment matched but different length */

  return 1; /* The part of LFN matched */
}

#if FF_FS_MINIMIZE <= 1 || FF_FS_RPATH >= 2 || FF_USE_LABEL || FF_FS_EXFAT
/*-----------------------------------------------------*/
/* FAT-LFN: Pick a part of file name from an LFN entry */
/*-----------------------------------------------------*/
static int pick_lfn(               /* 1:succeeded, 0:buffer overflow or invalid LFN entry */
                    WCHAR* lfnbuf, /* Pointer to the LFN working buffer */
                    BYTE* dir      /* Pointer to the LFN entry */
) {
  UINT i, s;
  WCHAR wc, uc;

  if (ld_word(dir + LDIR_FstClusLO) != 0) return 0; /* Check LDIR_FstClusLO is 0 */

  i = ((dir[LDIR_Ord] & ~LLEF) - 1) * 13; /* Offset in the LFN buffer */

  for (wc = 1, s = 0; s < 13; s++) { /* Process all characters in the entry */
    uc = ld_word(dir + LfnOfs[s]);   /* Pick an LFN character */
    if (wc) {
      if (i >= FF_MAX_LFN) return 0; /* Buffer overflow? */
      lfnbuf[i++] = wc = uc;         /* Store it */
    } else {
      if (uc != 0xFFFF) return 0; /* Check filler */
    }
  }

  if (dir[LDIR_Ord] & LLEF) {      /* Put terminator if it is the last LFN part */
    if (i >= FF_MAX_LFN) return 0; /* Buffer overflow? */
    lfnbuf[i] = 0;
  }

  return 1; /* The part of LFN is valid */
}
#endif

#if !FF_FS_READONLY
/*-----------------------------------------*/
/* FAT-LFN: Create an entry of LFN entries */
/*-----------------------------------------*/
static void put_lfn(const WCHAR* lfn, /* Pointer to the LFN */
                    BYTE* dir,        /* Pointer to the LFN entry to be created */
                    BYTE ord,         /* LFN order (1-20) */
                    BYTE sum          /* Checksum of the corresponding SFN */
) {
  UINT i, s;
  WCHAR wc;

  dir[LDIR_Chksum] = sum;  /* Set checksum */
  dir[LDIR_Attr] = AM_LFN; /* Set attribute. LFN entry */
  dir[LDIR_Type] = 0;
  st_word(dir + LDIR_FstClusLO, 0);

  i = (ord - 1) * 13; /* Get offset in the LFN working buffer */
  s = wc = 0;
  do {
    if (wc != 0xFFFF) wc = lfn[i++]; /* Get an effective character */
    st_word(dir + LfnOfs[s], wc);    /* Put it */
    if (wc == 0) wc = 0xFFFF;        /* Padding characters for left locations */
  } while (++s < 13);
  if (wc == 0xFFFF || !lfn[i]) ord |= LLEF; /* Last LFN part is the start of LFN sequence */
  dir[LDIR_Ord] = ord;                      /* Set the LFN order */
}

#endif /* !FF_FS_READONLY */
#endif /* FF_USE_LFN */

#if FF_USE_LFN && !FF_FS_READONLY
/*-----------------------------------------------------------------------*/
/* FAT-LFN: Create a Numbered SFN                                        */
/*-----------------------------------------------------------------------*/

static void gen_numname(BYTE* dst,        /* Pointer to the buffer to store numbered SFN */
                        const BYTE* src,  /* Pointer to SFN */
                        const WCHAR* lfn, /* Pointer to LFN */
                        UINT seq          /* Sequence number */
) {
  BYTE ns[8], c;
  UINT i, j;
  WCHAR wc;
  DWORD sr;

  mem_cpy(dst, src, 11);

  if (seq >
      5) { /* In case of many collisions, generate a hash number instead of sequential number */
    sr = seq;
    while (*lfn) { /* Create a CRC */
      wc = *lfn++;
      for (i = 0; i < 16; i++) {
        sr = (sr << 1) + (wc & 1);
        wc >>= 1;
        if (sr & 0x10000) sr ^= 0x11021;
      }
    }
    seq = (UINT)sr;
  }

  /* itoa (hexdecimal) */
  i = 7;
  do {
    c = (BYTE)((seq % 16) + '0');
    if (c > '9') c += 7;
    ns[i--] = c;
    seq /= 16;
  } while (seq);
  ns[i] = '~';

  /* Append the number to the SFN body */
  for (j = 0; j < i && dst[j] != ' '; j++) {
    if (dbc_1st(dst[j])) {
      if (j == i - 1) break;
      j++;
    }
  }
  do {
    dst[j++] = (i < 8) ? ns[i++] : ' ';
  } while (j < 8);
}
#endif /* FF_USE_LFN && !FF_FS_READONLY */

#if FF_USE_LFN
/*-----------------------------------------------------------------------*/
/* FAT-LFN: Calculate checksum of an SFN entry                           */
/*-----------------------------------------------------------------------*/

static BYTE sum_sfn(const BYTE* dir /* Pointer to the SFN entry */
) {
  BYTE sum = 0;
  UINT n = 11;

  do {
    sum = (sum >> 1) + (sum << 7) + *dir++;
  } while (--n);
  return sum;
}

#endif /* FF_USE_LFN */

#if FF_FS_EXFAT
/*-----------------------------------------------------------------------*/
/* exFAT: Checksum                                                       */
/*-----------------------------------------------------------------------*/

static WORD xdir_sum(                /* Get checksum of the directoly entry block */
                     const BYTE* dir /* Directory entry block to be calculated */
) {
  UINT i, szblk;
  WORD sum;

  szblk = (dir[XDIR_NumSec] + 1) * SZDIRE;
  for (i = sum = 0; i < szblk; i++) {
    if (i == XDIR_SetSum) { /* Skip sum field */
      i++;
    } else {
      sum = ((sum & 1) ? 0x8000 : 0) + (sum >> 1) + dir[i];
    }
  }
  return sum;
}

static WORD xname_sum(                  /* Get check sum (to be used as hash) of the name */
                      const WCHAR* name /* File name to be calculated */
) {
  WCHAR chr;
  WORD sum = 0;

  while ((chr = *name++) != 0) {
    chr = ff_wtoupper(chr); /* File name needs to be upper-case converted */
    sum = ((sum & 1) ? 0x8000 : 0) + (sum >> 1) + (chr & 0xFF);
    sum = ((sum & 1) ? 0x8000 : 0) + (sum >> 1) + (chr >> 8);
  }
  return sum;
}

#if !FF_FS_READONLY && FF_USE_MKFS
static DWORD xsum32(BYTE dat, /* Byte to be calculated */
                    DWORD sum /* Previous sum */
) {
  sum = ((sum & 1) ? 0x80000000 : 0) + (sum >> 1) + dat;
  return sum;
}
#endif

#if FF_FS_MINIMIZE <= 1 || FF_FS_RPATH >= 2
/*------------------------------------------------------*/
/* exFAT: Get object information from a directory block */
/*------------------------------------------------------*/

static void get_xdir_info(BYTE* dirb,  /* Pointer to the direcotry entry block 85+C0+C1s */
                          FILINFO* fno /* Buffer to store the extracted file information */
) {
  WCHAR w;
  UINT di, si, nc;

  /* Get file name */
  for (si = SZDIRE * 2, nc = di = 0; nc < dirb[XDIR_NumName]; si += 2, nc++) {
    if ((si % SZDIRE) == 0) si += 2;     /* Skip entry type field */
    w = ld_word(dirb + si);              /* Get a character */
#if !FF_LFN_UNICODE                      /* ANSI/OEM API */
    w = ff_uni2oem(w, CODEPAGE);         /* Convert it to OEM code */
    if (w >= 0x100) {                    /* Is it a double byte char? */
      fno->fname[di++] = (char)(w >> 8); /* Store 1st byte of the DBC */
    }
#endif
    if (w == 0 || di >= FF_MAX_LFN) {
      di = 0;
      break;
    }                            /* Invalid char or buffer overflow --> inaccessible object name */
    fno->fname[di++] = (TCHAR)w; /* Store the character */
  }
  if (di == 0) fno->fname[di++] = '?'; /* Inaccessible object name? */
  fno->fname[di] = 0;                  /* Terminate file name */

  fno->altname[0] = 0;                                                       /* No SFN */
  fno->fattrib = dirb[XDIR_Attr];                                            /* Attribute */
  fno->fsize = (fno->fattrib & AM_DIR) ? 0 : ld_qword(dirb + XDIR_FileSize); /* Size */
  fno->ftime = ld_word(dirb + XDIR_ModTime + 0);                             /* Time */
  fno->fdate = ld_word(dirb + XDIR_ModTime + 2);                             /* Date */
}

#endif /* FF_FS_MINIMIZE <= 1 || FF_FS_RPATH >= 2 */

/*-----------------------------------*/
/* exFAT: Get a directry entry block */
/*-----------------------------------*/

static FRESULT
load_xdir(           /* FR_INT_ERR: invalid entry block */
          FF_DIR* dp /* Reading direcotry object pointing top of the entry block to load */
) {
  FRESULT res;
  UINT i, sz_ent;
  BYTE* dirb = dp->obj.fs->dirbuf; /* Pointer to the on-memory direcotry entry block 85+C0+C1s */

  /* Load 85 entry */
  res = move_window(dp->obj.fs, dp->sect);
  if (res != FR_OK) return res;
  if (dp->dir[XDIR_Type] != 0x85) return FR_INT_ERR; /* Invalid order */
  mem_cpy(dirb + 0 * SZDIRE, dp->dir, SZDIRE);
  sz_ent = (dirb[XDIR_NumSec] + 1) * SZDIRE;
  if (sz_ent < 3 * SZDIRE || sz_ent > 19 * SZDIRE) return FR_INT_ERR;

  /* Load C0 entry */
  res = dir_next(dp, 0);
  if (res == FR_NO_FILE) res = FR_INT_ERR; /* It cannot be */
  if (res != FR_OK) return res;
  res = move_window(dp->obj.fs, dp->sect);
  if (res != FR_OK) return res;
  if (dp->dir[XDIR_Type] != 0xC0) return FR_INT_ERR; /* Invalid order */
  mem_cpy(dirb + 1 * SZDIRE, dp->dir, SZDIRE);
  if (MAXDIRB(dirb[XDIR_NumName]) > sz_ent) return FR_INT_ERR;

  /* Load C1 entries */
  i = 2 * SZDIRE; /* C1 offset to load */
  do {
    res = dir_next(dp, 0);
    if (res == FR_NO_FILE) res = FR_INT_ERR; /* It cannot be */
    if (res != FR_OK) return res;
    res = move_window(dp->obj.fs, dp->sect);
    if (res != FR_OK) return res;
    if (dp->dir[XDIR_Type] != 0xC1) return FR_INT_ERR; /* Invalid order */
    if (i < MAXDIRB(FF_MAX_LFN)) mem_cpy(dirb + i, dp->dir, SZDIRE);
  } while ((i += SZDIRE) < sz_ent);

  /* Sanity check (do it for only accessible object) */
  if (i <= MAXDIRB(FF_MAX_LFN)) {
    if (xdir_sum(dirb) != ld_word(dirb + XDIR_SetSum)) return FR_INT_ERR;
  }
  return FR_OK;
}

#if !FF_FS_READONLY || FF_FS_RPATH != 0
/*------------------------------------------------*/
/* exFAT: Load the object's directory entry block */
/*------------------------------------------------*/
static FRESULT load_obj_xdir(
    FF_DIR* dp,        /* Blank directory object to be used to access containing direcotry */
    const FFOBJID* obj /* Object with its containing directory information */
) {
  FRESULT res;

  /* Open object containing directory */
  dp->obj.fs = obj->fs;
  dp->obj.sclust = obj->c_scl;
  dp->obj.stat = (BYTE)obj->c_size;
  dp->obj.objsize = obj->c_size & 0xFFFFFF00;
  dp->obj.n_frag = 0;
  dp->blk_ofs = obj->c_ofs;

  res = dir_sdi(dp, dp->blk_ofs); /* Goto object's entry block */
  if (res == FR_OK) {
    res = load_xdir(dp); /* Load the object's entry block */
  }
  return res;
}
#endif

#if !FF_FS_READONLY
/*----------------------------------------*/
/* exFAT: Store the directory entry block */
/*----------------------------------------*/
static FRESULT store_xdir(FF_DIR* dp /* Pointer to the direcotry object */
) {
  FRESULT res;
  UINT nent;
  BYTE* dirb = dp->obj.fs->dirbuf; /* Pointer to the direcotry entry block 85+C0+C1s */

  /* Create set sum */
  st_word(dirb + XDIR_SetSum, xdir_sum(dirb));
  nent = dirb[XDIR_NumSec] + 1;

  /* Store the direcotry entry block to the directory */
  res = dir_sdi(dp, dp->blk_ofs);
  while (res == FR_OK) {
    res = move_window(dp->obj.fs, dp->sect);
    if (res != FR_OK) break;
    mem_cpy(dp->dir, dirb, SZDIRE);
    dp->obj.fs->wflag = 1;
    if (--nent == 0) break;
    dirb += SZDIRE;
    res = dir_next(dp, 0);
  }
  return (res == FR_OK || res == FR_DISK_ERR) ? res : FR_INT_ERR;
}

/*-------------------------------------------*/
/* exFAT: Create a new directory enrty block */
/*-------------------------------------------*/

static void create_xdir(BYTE* dirb,      /* Pointer to the direcotry entry block buffer */
                        const WCHAR* lfn /* Pointer to the object name */
) {
  UINT i;
  BYTE nc1, nlen;
  WCHAR chr;

  /* Create 85+C0 entry */
  mem_set(dirb, 0, 2 * SZDIRE);
  dirb[0 * SZDIRE + XDIR_Type] = 0x85;
  dirb[1 * SZDIRE + XDIR_Type] = 0xC0;

  /* Create C1 entries */
  nlen = nc1 = 0;
  chr = 1;
  i = SZDIRE * 2;
  do {
    dirb[i++] = 0xC1;
    dirb[i++] = 0;                               /* Entry type C1 */
    do {                                         /* Fill name field */
      if (chr && (chr = lfn[nlen]) != 0) nlen++; /* Get a character if exist */
      st_word(dirb + i, chr);                    /* Store it */
      i += 2;
    } while (i % SZDIRE != 0);
    nc1++;
  } while (lfn[nlen]); /* Fill next entry if any char follows */

  dirb[XDIR_NumName] = nlen;                     /* Set name length */
  dirb[XDIR_NumSec] = 1 + nc1;                   /* Set secondary count */
  st_word(dirb + XDIR_NameHash, xname_sum(lfn)); /* Set name hash */
}

#endif /* !FF_FS_READONLY */
#endif /* FF_FS_EXFAT */

#if FF_FS_MINIMIZE <= 1 || FF_FS_RPATH >= 2 || FF_USE_LABEL || FF_FS_EXFAT
/*-----------------------------------------------------------------------*/
/* Read an object from the directory                                     */
/*-----------------------------------------------------------------------*/

static FRESULT dir_read(FF_DIR* dp, /* Pointer to the directory object */
                        int vol     /* Filtered by 0:file/directory or 1:volume label */
) {
  FRESULT res = FR_NO_FILE;
  FATFS* fs = dp->obj.fs;
  BYTE a, c;
#if FF_USE_LFN
  BYTE ord = 0xFF, sum = 0xFF;
#endif

  while (dp->sect) {
    res = move_window(fs, dp->sect);
    if (res != FR_OK) break;
    c = dp->dir[DIR_Name]; /* Test for the entry type */
    if (c == 0) {
      res = FR_NO_FILE;
      break; /* Reached to end of the directory */
    }
#if FF_FS_EXFAT
    if (fs->fs_type == FS_EXFAT) { /* On the exFAT volume */
      if (FF_USE_LABEL && vol) {
        if (c == 0x83) break; /* Volume label entry? */
      } else {
        if (c == 0x85) {          /* Start of the file entry block? */
          dp->blk_ofs = dp->dptr; /* Get location of the block */
          res = load_xdir(dp);    /* Load the entry block */
          if (res == FR_OK) {
            dp->obj.attr = fs->dirbuf[XDIR_Attr] & AM_MASK; /* Get attribute */
          }
          break;
        }
      }
    } else
#endif
    {                                                 /* On the FAT/FAT32 volume */
      dp->obj.attr = a = dp->dir[DIR_Attr] & AM_MASK; /* Get attribute */
#if FF_USE_LFN                                        /* LFN configuration */
      if (c == DDEM || c == '.' ||
          (int)((a & ~AM_ARC) == AM_VOL) != vol) { /* An entry without valid data */
        ord = 0xFF;
      } else {
        if (a == AM_LFN) { /* An LFN entry is found */
          if (c & LLEF) {  /* Is it start of an LFN sequence? */
            sum = dp->dir[LDIR_Chksum];
            c &= (BYTE)~LLEF;
            ord = c;
            dp->blk_ofs = dp->dptr;
          }
          /* Check LFN validity and capture it */
          ord = (c == ord && sum == dp->dir[LDIR_Chksum] && pick_lfn(fs->lfnbuf, dp->dir)) ? ord - 1
                                                                                           : 0xFF;
        } else {                                /* An SFN entry is found */
          if (ord || sum != sum_sfn(dp->dir)) { /* Is there a valid LFN? */
            dp->blk_ofs = 0xFFFFFFFF;           /* It has no LFN. */
          }
          break;
        }
      }
#else /* Non LFN configuration */
      if (c != DDEM && c != '.' && a != AM_LFN &&
          (int)((a & ~AM_ARC) == AM_VOL) == vol) { /* Is it a valid entry? */
        break;
      }
#endif
    }
    res = dir_next(dp, 0); /* Next entry */
    if (res != FR_OK) break;
  }

  if (res != FR_OK) dp->sect = 0; /* Terminate the read operation on error or EOT */
  return res;
}

#endif /* FF_FS_MINIMIZE <= 1 || FF_USE_LABEL || FF_FS_RPATH >= 2 */

/*-----------------------------------------------------------------------*/
/* Directory handling - Find an object in the directory                  */
/*-----------------------------------------------------------------------*/

static FRESULT dir_find(           /* FR_OK(0):succeeded, !=0:error */
                        FF_DIR* dp /* Pointer to the directory object with the file name */
) {
  FRESULT res;
  FATFS* fs = dp->obj.fs;
  BYTE c;
#if FF_USE_LFN
  BYTE a, ord, sum;
#endif

  res = dir_sdi(dp, 0); /* Rewind directory object */
  if (res != FR_OK) return res;
#if FF_FS_EXFAT
  if (fs->fs_type == FS_EXFAT) { /* On the exFAT volume */
    BYTE nc;
    UINT di, ni;
    WORD hash = xname_sum(fs->lfnbuf); /* Hash value of the name to find */

    while ((res = dir_read(dp, 0)) == FR_OK) { /* Read an item */
#if FF_MAX_LFN < 255
      if (fs->dirbuf[XDIR_NumName] > FF_MAX_LFN)
        continue; /* Skip comparison if inaccessible object name */
#endif
      if (ld_word(fs->dirbuf + XDIR_NameHash) != hash)
        continue; /* Skip comparison if hash mismatched */
      for (nc = fs->dirbuf[XDIR_NumName], di = SZDIRE * 2, ni = 0; nc;
           nc--, di += 2, ni++) { /* Compare the name */
        if ((di % SZDIRE) == 0) di += 2;
        if (ff_wtoupper(ld_word(fs->dirbuf + di)) != ff_wtoupper(fs->lfnbuf[ni])) break;
      }
      if (nc == 0 && !fs->lfnbuf[ni]) break; /* Name matched? */
    }
    return res;
  }
#endif
  /* On the FAT/FAT32 volume */
#if FF_USE_LFN
  ord = sum = 0xFF;
  dp->blk_ofs = 0xFFFFFFFF; /* Reset LFN sequence */
#endif
  do {
    res = move_window(fs, dp->sect);
    if (res != FR_OK) break;
    c = dp->dir[DIR_Name];
    if (c == 0) {
      res = FR_NO_FILE;
      break;
    }          /* Reached to end of table */
#if FF_USE_LFN /* LFN configuration */
    dp->obj.attr = a = dp->dir[DIR_Attr] & AM_MASK;
    if (c == DDEM || ((a & AM_VOL) && a != AM_LFN)) { /* An entry without valid data */
      ord = 0xFF;
      dp->blk_ofs = 0xFFFFFFFF; /* Reset LFN sequence */
    } else {
      if (a == AM_LFN) { /* An LFN entry is found */
        if (!(dp->fn[NSFLAG] & NS_NOLFN)) {
          if (c & LLEF) { /* Is it start of LFN sequence? */
            sum = dp->dir[LDIR_Chksum];
            c &= (BYTE)~LLEF;
            ord = c;                /* LFN start order */
            dp->blk_ofs = dp->dptr; /* Start offset of LFN */
          }
          /* Check validity of the LFN entry and compare it with given name */
          ord = (c == ord && sum == dp->dir[LDIR_Chksum] && cmp_lfn(fs->lfnbuf, dp->dir)) ? ord - 1
                                                                                          : 0xFF;
        }
      } else {                                      /* An SFN entry is found */
        if (!ord && sum == sum_sfn(dp->dir)) break; /* LFN matched? */
        if (!(dp->fn[NSFLAG] & NS_LOSS) && !mem_cmp(dp->dir, dp->fn, 11)) break; /* SFN matched? */
        ord = 0xFF;
        dp->blk_ofs = 0xFFFFFFFF; /* Reset LFN sequence */
      }
    }
#else /* Non LFN configuration */
    dp->obj.attr = dp->dir[DIR_Attr] & AM_MASK;
    if (!(dp->dir[DIR_Attr] & AM_VOL) && !mem_cmp(dp->dir, dp->fn, 11))
      break; /* Is it a valid entry? */
#endif
    res = dir_next(dp, 0); /* Next entry */
  } while (res == FR_OK);

  return res;
}

#if !FF_FS_READONLY
/*-----------------------------------------------------------------------*/
/* Register an object to the directory                                   */
/*-----------------------------------------------------------------------*/

static FRESULT
dir_register(/* FR_OK:succeeded, FR_DENIED:no free entry or too many SFN collision, FR_DISK_ERR:disk error */
             FF_DIR* dp /* Target directory with object name to be created */
) {
  FRESULT res;
  FATFS* fs = dp->obj.fs;
#if FF_USE_LFN /* LFN configuration */
  UINT n, nlen, nent;
  BYTE sn[12], sum;

  if (dp->fn[NSFLAG] & (NS_DOT | NS_NONAME)) return FR_INVALID_NAME; /* Check name validity */
  for (nlen = 0; fs->lfnbuf[nlen]; nlen++)
    ; /* Get lfn length */

#if FF_FS_EXFAT
  if (fs->fs_type == FS_EXFAT) { /* On the exFAT volume */
    nent = (nlen + 14) / 15 + 2; /* Number of entries to allocate (85+C0+C1s) */
    res = dir_alloc(dp, nent);   /* Allocate entries */
    if (res != FR_OK) return res;
    dp->blk_ofs = dp->dptr - SZDIRE * (nent - 1); /* Set the allocated entry block offset */

    if (dp->obj.stat & 4) { /* Has the directory been stretched? */
      dp->obj.stat &= ~4;
      res = fill_first_frag(&dp->obj); /* Fill the first fragment on the FAT if needed */
      if (res != FR_OK) return res;
      res = fill_last_frag(&dp->obj, dp->clust,
                           0xFFFFFFFF); /* Fill the last fragment on the FAT if needed */
      if (res != FR_OK) return res;
      if (dp->obj.sclust != 0) { /* Is it a sub directory? */
        FF_DIR dj;

        res = load_obj_xdir(&dj, &dp->obj); /* Load the object status */
        if (res != FR_OK) return res;
        dp->obj.objsize +=
            (DWORD)fs->csize * SS(fs); /* Increase the directory size by cluster size */
        st_qword(fs->dirbuf + XDIR_FileSize, dp->obj.objsize); /* Update the allocation status */
        st_qword(fs->dirbuf + XDIR_ValidFileSize, dp->obj.objsize);
        fs->dirbuf[XDIR_GenFlags] = dp->obj.stat | 1;
        res = store_xdir(&dj); /* Store the object status */
        if (res != FR_OK) return res;
      }
    }

    create_xdir(fs->dirbuf, fs->lfnbuf); /* Create on-memory directory block to be written later */
    return FR_OK;
  }
#endif
  /* On the FAT/FAT32 volume */
  mem_cpy(sn, dp->fn, 12);
  if (sn[NSFLAG] & NS_LOSS) {  /* When LFN is out of 8.3 format, generate a numbered name */
    dp->fn[NSFLAG] = NS_NOLFN; /* Find only SFN */
    for (n = 1; n < 100; n++) {
      gen_numname(dp->fn, sn, fs->lfnbuf, n); /* Generate a numbered name */
      res = dir_find(dp);                     /* Check if the name collides with existing SFN */
      if (res != FR_OK) break;
    }
    if (n == 100) return FR_DENIED;    /* Abort if too many collisions */
    if (res != FR_NO_FILE) return res; /* Abort if the result is other than 'not collided' */
    dp->fn[NSFLAG] = sn[NSFLAG];
  }

  /* Create an SFN with/without LFNs. */
  nent = (sn[NSFLAG] & NS_LFN) ? (nlen + 12) / 13 + 1 : 1; /* Number of entries to allocate */
  res = dir_alloc(dp, nent);                               /* Allocate entries */
  if (res == FR_OK && --nent) {                            /* Set LFN entry if needed */
    res = dir_sdi(dp, dp->dptr - nent * SZDIRE);
    if (res == FR_OK) {
      sum = sum_sfn(dp->fn); /* Checksum value of the SFN tied to the LFN */
      do {                   /* Store LFN entries in bottom first */
        res = move_window(fs, dp->sect);
        if (res != FR_OK) break;
        put_lfn(fs->lfnbuf, dp->dir, (BYTE)nent, sum);
        fs->wflag = 1;
        res = dir_next(dp, 0); /* Next entry */
      } while (res == FR_OK && --nent);
    }
  }

#else /* Non LFN configuration */
  res = dir_alloc(dp, 1); /* Allocate an entry for SFN */

#endif

  /* Set SFN entry */
  if (res == FR_OK) {
    res = move_window(fs, dp->sect);
    if (res == FR_OK) {
      mem_set(dp->dir, 0, SZDIRE);             /* Clean the entry */
      mem_cpy(dp->dir + DIR_Name, dp->fn, 11); /* Put SFN */
#if FF_USE_LFN
      dp->dir[DIR_NTres] = dp->fn[NSFLAG] & (NS_BODY | NS_EXT); /* Put NT flag */
#endif
      fs->wflag = 1;
    }
  }

  return res;
}

#endif /* !FF_FS_READONLY */

#if !FF_FS_READONLY && FF_FS_MINIMIZE == 0
/*-----------------------------------------------------------------------*/
/* Remove an object from the directory                                   */
/*-----------------------------------------------------------------------*/

static FRESULT dir_remove(           /* FR_OK:Succeeded, FR_DISK_ERR:A disk error */
                          FF_DIR* dp /* Directory object pointing the entry to be removed */
) {
  FRESULT res;
  FATFS* fs = dp->obj.fs;
#if FF_USE_LFN /* LFN configuration */
  DWORD last = dp->dptr;

  res = (dp->blk_ofs == 0xFFFFFFFF)
            ? FR_OK
            : dir_sdi(dp, dp->blk_ofs); /* Goto top of the entry block if LFN is exist */
  if (res == FR_OK) {
    do {
      res = move_window(fs, dp->sect);
      if (res != FR_OK) break;
      /* Mark an entry 'deleted' */
      if (FF_FS_EXFAT && fs->fs_type == FS_EXFAT) { /* On the exFAT volume */
        dp->dir[XDIR_Type] &= 0x7F;
      } else { /* On the FAT/FAT32 volume */
        dp->dir[DIR_Name] = DDEM;
      }
      fs->wflag = 1;
      if (dp->dptr >= last)
        break; /* If reached last entry then all entries of the object has been deleted. */
      res = dir_next(dp, 0); /* Next entry */
    } while (res == FR_OK);
    if (res == FR_NO_FILE) res = FR_INT_ERR;
  }
#else /* Non LFN configuration */

  res = move_window(fs, dp->sect);
  if (res == FR_OK) {
    dp->dir[DIR_Name] = DDEM;
    fs->wflag = 1;
  }
#endif

  return res;
}

#endif /* !FF_FS_READONLY && FF_FS_MINIMIZE == 0 */

#if FF_FS_MINIMIZE <= 1 || FF_FS_RPATH >= 2
/*-----------------------------------------------------------------------*/
/* Get file information from directory entry                             */
/*-----------------------------------------------------------------------*/

static void get_fileinfo(             /* No return code */
                         FF_DIR* dp,  /* Pointer to the directory object */
                         FILINFO* fno /* Pointer to the file information to be filled */
) {
  UINT i, j;
  TCHAR c;
  DWORD tm;
#if FF_USE_LFN
  WCHAR w, lfv;
  FATFS* fs = dp->obj.fs;
#endif

  fno->fname[0] = 0;         /* Invaidate file info */
  if (dp->sect == 0) return; /* Exit if read pointer has reached end of directory */

#if FF_USE_LFN /* LFN configuration */
#if FF_FS_EXFAT
  if (fs->fs_type == FS_EXFAT) { /* On the exFAT volume */
    get_xdir_info(fs->dirbuf, fno);
    return;
  } else
#endif
  {                                  /* On the FAT/FAT32 volume */
    if (dp->blk_ofs != 0xFFFFFFFF) { /* Get LFN if available */
      i = j = 0;
      while ((w = fs->lfnbuf[j++]) != 0) { /* Get an LFN character */
#if !FF_LFN_UNICODE                        /* ANSI/OEM API */
        w = ff_uni2oem(w, CODEPAGE);       /* Unicode -> OEM */
        if (w == 0) {
          i = 0;
          break;
        }                 /* No LFN if it could not be converted */
        if (w >= 0x100) { /* Put 1st byte if it is a DBC */
          fno->fname[i++] = (char)(w >> 8);
        }
#endif
        if (i >= FF_MAX_LFN) {
          i = 0;
          break;
        } /* No LFN if buffer overflow */
        fno->fname[i++] = (TCHAR)w;
      }
      fno->fname[i] = 0; /* Terminate the LFN */
    }
  }

  i = j = 0;
  lfv = fno->fname[i]; /* LFN is exist if non-zero */
  while (i < 11) {     /* Copy name body and extension */
    c = (TCHAR)dp->dir[i++];
    if (c == ' ') continue;          /* Skip padding spaces */
    if (c == RDDEM) c = (TCHAR)DDEM; /* Restore replaced DDEM character */
    if (i == 9) {                    /* Insert a . if extension is exist */
      if (!lfv) fno->fname[j] = '.';
      fno->altname[j++] = '.';
    }
#if FF_LFN_UNICODE /* Unicode API */
    if (dbc_1st((BYTE)c) && i != 8 && i != 11 && dbc_2nd(dp->dir[i])) {
      c = c << 8 | dp->dir[i++];
    }
    c = ff_oem2uni(c, CODEPAGE); /* OEM -> Unicode */
    if (!c) c = '?';
#endif
    fno->altname[j] = c;
    if (!lfv) {
      if (IsUpper(c) && (dp->dir[DIR_NTres] & ((i >= 9) ? NS_EXT : NS_BODY))) {
        c += 0x20; /* To lower */
      }
      fno->fname[j] = c;
    }
    j++;
  }
  if (!lfv) {
    fno->fname[j] = 0;
    if (!dp->dir[DIR_NTres])
      j = 0; /* Altname is no longer needed if neither LFN nor case info is exist. */
  }
  fno->altname[j] = 0; /* Terminate the SFN */

#else /* Non-LFN configuration */
  i = j = 0;
  while (i < 11) { /* Copy name body and extension */
    c = (TCHAR)dp->dir[i++];
    if (c == ' ') continue;            /* Skip padding spaces */
    if (c == RDDEM) c = (TCHAR)DDEM;   /* Restore replaced DDEM character */
    if (i == 9) fno->fname[j++] = '.'; /* Insert a . if extension is exist */
    fno->fname[j++] = c;
  }
  fno->fname[j] = 0;
#endif

  fno->fattrib = dp->dir[DIR_Attr];              /* Attribute */
  fno->fsize = ld_dword(dp->dir + DIR_FileSize); /* Size */
  tm = ld_dword(dp->dir + DIR_ModTime);          /* Timestamp */
  fno->ftime = (WORD)tm;
  fno->fdate = (WORD)(tm >> 16);
}

#endif /* FF_FS_MINIMIZE <= 1 || FF_FS_RPATH >= 2 */

#if FF_USE_FIND && FF_FS_MINIMIZE <= 1
/*-----------------------------------------------------------------------*/
/* Pattern matching                                                      */
/*-----------------------------------------------------------------------*/

static WCHAR get_achar(                  /* Get a character and advances ptr 1 or 2 */
                       const TCHAR** ptr /* Pointer to pointer to the SBCS/DBCS/Unicode string */
) {
  WCHAR chr;

#if FF_LFN_UNICODE && FF_USE_LFN /* Unicode API */
  chr = ff_wtoupper(*(*ptr)++);  /* Get a Unicode char and to upper */
#else                            /* ANSI/OEM API */
  chr = (BYTE) * (*ptr)++;                            /* Get a byte */
  if (IsLower(chr)) chr -= 0x20;                      /* To upper ASCII char */
#if FF_CODE_PAGE == 0
  if (ExCvt && chr >= 0x80) chr = ExCvt[chr - 0x80];  /* To upper SBCS extended char */
#elif FF_CODE_PAGE < 900
  if (chr >= 0x80) chr = ExCvt[chr - 0x80]; /* To upper SBCS extended char */
#endif
#if FF_CODE_PAGE == 0 || FF_CODE_PAGE >= 900
  if (dbc_1st((BYTE)chr) && dbc_2nd((BYTE) * *ptr)) { /* Get DBC 2nd byte if needed */
    chr = chr << 8 | (BYTE) * (*ptr)++;
  }
#endif
#endif
  return chr;
}

static int pattern_matching(                  /* 0:not matched, 1:matched */
                            const TCHAR* pat, /* Matching pattern */
                            const TCHAR* nam, /* String to be tested */
                            int skip,         /* Number of pre-skip chars (number of ?s) */
                            int inf           /* Infinite search (* specified) */
) {
  const TCHAR *pp, *np;
  WCHAR pc, nc;
  int nm, nx;

  while (skip--) {                  /* Pre-skip name chars */
    if (!get_achar(&nam)) return 0; /* Branch mismatched if less name chars */
  }
  if (!*pat && inf) return 1; /* (short circuit) */

  do {
    pp = pat;
    np = nam; /* Top of pattern and name to match */
    for (;;) {
      if (*pp == '?' || *pp == '*') { /* Wildcard? */
        nm = nx = 0;
        do { /* Analyze the wildcard chars */
          if (*pp++ == '?')
            nm++;
          else
            nx = 1;
        } while (*pp == '?' || *pp == '*');
        if (pattern_matching(pp, np, nm, nx))
          return 1; /* Test new branch (recurs upto number of wildcard blocks in the pattern) */
        nc = *np;
        break; /* Branch mismatched */
      }
      pc = get_achar(&pp);   /* Get a pattern char */
      nc = get_achar(&np);   /* Get a name char */
      if (pc != nc) break;   /* Branch mismatched? */
      if (pc == 0) return 1; /* Branch matched? (matched at end of both strings) */
    }
    get_achar(&nam);   /* nam++ */
  } while (inf && nc); /* Retry until end of name if infinite search is specified */

  return 0;
}

#endif /* FF_USE_FIND && FF_FS_MINIMIZE <= 1 */

/*-----------------------------------------------------------------------*/
/* Pick a top segment and create the object name in directory form       */
/*-----------------------------------------------------------------------*/

static FRESULT
create_name(                   /* FR_OK: successful, FR_INVALID_NAME: could not create */
            FF_DIR* dp,        /* Pointer to the directory object */
            const TCHAR** path /* Pointer to pointer to the segment in the path string */
) {
#if FF_USE_LFN /* LFN configuration */
  BYTE b, cf;
  WCHAR w, *lfn;
  UINT i, ni, si, di;
  const TCHAR* p;

  /* Create LFN in Unicode */
  p = *path;
  lfn = dp->obj.fs->lfnbuf;
  si = di = 0;
  for (;;) {
    w = p[si++];                                  /* Get a character */
    if (w < ' ') break;                           /* Break if end of the path name */
    if (w == '/' || w == '\\') {                  /* Break if a separator is found */
      while (p[si] == '/' || p[si] == '\\') si++; /* Skip duplicated separator if exist */
      break;
    }
    if (di >= FF_MAX_LFN) return FR_INVALID_NAME; /* Reject too long name */
#if !FF_LFN_UNICODE                               /* ANSI/OEM API */
    w &= 0xFF;
    if (dbc_1st((BYTE)w)) {                    /* Check if it is a DBC 1st byte */
      b = (BYTE)p[si++];                       /* Get 2nd byte */
      w = (w << 8) + b;                        /* Create a DBC */
      if (!dbc_2nd(b)) return FR_INVALID_NAME; /* Reject invalid sequence */
    }
    w = ff_oem2uni(w, CODEPAGE);    /* Convert ANSI/OEM to Unicode */
    if (!w) return FR_INVALID_NAME; /* Reject invalid code */
#endif
    if (w < 0x80 && chk_chr("\"*:<>\?|\x7F", w))
      return FR_INVALID_NAME; /* Reject illegal characters for LFN */
    lfn[di++] = w;            /* Store the Unicode character */
  }
  *path = &p[si];               /* Return pointer to the next segment */
  cf = (w < ' ') ? NS_LAST : 0; /* Set last segment flag if end of the path */
#if FF_FS_RPATH != 0
  if ((di == 1 && lfn[di - 1] == '.') ||
      (di == 2 && lfn[di - 1] == '.' && lfn[di - 2] == '.')) { /* Is this segment a dot name? */
    lfn[di] = 0;
    for (i = 0; i < 11; i++) /* Create dot name for SFN entry */
      dp->fn[i] = (i < di) ? '.' : ' ';
    dp->fn[i] = cf | NS_DOT; /* This is a dot entry */
    return FR_OK;
  }
#endif
  while (di) { /* Snip off trailing spaces and dots if exist */
    w = lfn[di - 1];
    if (w != ' ' && w != '.') break;
    di--;
  }
  lfn[di] = 0;                         /* LFN is created */
  if (di == 0) return FR_INVALID_NAME; /* Reject nul name */

  /* Create SFN in directory form */
  mem_set(dp->fn, ' ', 11);
  for (si = 0; lfn[si] == ' ' || lfn[si] == '.'; si++)
    ; /* Strip leading spaces and dots */
  if (si > 0) cf |= NS_LOSS | NS_LFN;
  while (di > 0 && lfn[di - 1] != '.') di--; /* Find extension (di<=si: no extension) */

  i = b = 0;
  ni = 8;
  for (;;) {
    w = lfn[si++];                            /* Get an LFN character */
    if (!w) break;                            /* Break on end of the LFN */
    if (w == ' ' || (w == '.' && si != di)) { /* Remove spaces and dots */
      cf |= NS_LOSS | NS_LFN;
      continue;
    }

    if (i >= ni || si == di) { /* Entered extension or end of SFN */
      if (ni == 11) {          /* Extension fileld overflow? */
        cf |= NS_LOSS | NS_LFN;
        break;
      }
      if (si != di) cf |= NS_LOSS | NS_LFN; /* Out of 8.3 format */
      if (si > di) break;                   /* No extension */
      si = di;
      i = 8;
      ni = 11; /* Enter extension fileld */
      b <<= 2;
      continue;
    }

    if (w >= 0x80) { /* Is this a non-ASCII character? */
      cf |= NS_LFN;  /* Force to create LFN entry */
#if FF_CODE_PAGE == 0
      if (ExCvt) {                                /* In SBCS */
        w = ff_uni2oem(w, CODEPAGE);              /* Unicode -> OEM code */
        if (w & 0x80) w = ExCvt[w & 0x7F];        /* Convert extended character to upper (SBCS) */
      } else {                                    /* In DBCS */
        w = ff_uni2oem(ff_wtoupper(w), CODEPAGE); /* Upper converted Unicode -> OEM code */
      }
#elif FF_CODE_PAGE < 900 /* SBCS cfg */
      w = ff_uni2oem(w, CODEPAGE);       /* Unicode -> OEM code */
      if (w & 0x80) w = ExCvt[w & 0x7F]; /* Convert extended character to upper (SBCS) */
#else                    /* DBCS cfg */
      w = ff_uni2oem(ff_wtoupper(w), CODEPAGE); /* Upper converted Unicode -> OEM code */
#endif
    }

    if (w >= 0x100) {    /* Is this a DBC? */
      if (i >= ni - 1) { /* Field overflow? */
        cf |= NS_LOSS | NS_LFN;
        i = ni;
        continue; /* Next field */
      }
      dp->fn[i++] = (BYTE)(w >> 8);     /* Put 1st byte */
    } else {                            /* SBC */
      if (!w || chk_chr("+,;=[]", w)) { /* Replace illegal characters for SFN */
        w = '_';
        cf |= NS_LOSS | NS_LFN; /* Lossy conversion */
      } else {
        if (IsUpper(w)) { /* ASCII large capital */
          b |= 2;
        } else {
          if (IsLower(w)) { /* ASCII small capital */
            b |= 1;
            w -= 0x20;
          }
        }
      }
    }
    dp->fn[i++] = (BYTE)w;
  }

  if (dp->fn[0] == DDEM)
    dp->fn[0] = RDDEM; /* If the first character collides with DDEM, replace it with RDDEM */

  if (ni == 8) b <<= 2;
  if ((b & 0x0C) == 0x0C || (b & 0x03) == 0x03)
    cf |= NS_LFN; /* Create LFN entry when there are composite capitals */
  if (!(cf &
        NS_LFN)) { /* When LFN is in 8.3 format without extended character, NT flags are created */
    if ((b & 0x03) == 0x01) cf |= NS_EXT;  /* NT flag (Extension has only small capital) */
    if ((b & 0x0C) == 0x04) cf |= NS_BODY; /* NT flag (Filename has only small capital) */
  }

  dp->fn[NSFLAG] = cf; /* SFN is created */

  return FR_OK;

#else /* FF_USE_LFN : Non-LFN configuration */
  BYTE c, d, *sfn;
  UINT ni, si, i;
  const char* p;

  /* Create file name in directory form */
  p = *path;
  sfn = dp->fn;
  mem_set(sfn, ' ', 11);
  si = i = 0;
  ni = 8;
#if FF_FS_RPATH != 0
  if (p[si] == '.') { /* Is this a dot entry? */
    for (;;) {
      c = (BYTE)p[si++];
      if (c != '.' || si >= 3) break;
      sfn[i++] = c;
    }
    if (c != '/' && c != '\\' && c > ' ') return FR_INVALID_NAME;
    *path = p + si; /* Return pointer to the next segment */
    sfn[NSFLAG] =
        (c <= ' ') ? NS_LAST | NS_DOT : NS_DOT; /* Set last segment flag if end of the path */
    return FR_OK;
  }
#endif
  for (;;) {
    c = (BYTE)p[si++];
    if (c <= ' ') break;                          /* Break if end of the path name */
    if (c == '/' || c == '\\') {                  /* Break if a separator is found */
      while (p[si] == '/' || p[si] == '\\') si++; /* Skip duplicated separator if exist */
      break;
    }
    if (c == '.' || i >= ni) {                          /* End of body or over size? */
      if (ni == 11 || c != '.') return FR_INVALID_NAME; /* Over size or invalid dot */
      i = 8;
      ni = 11; /* Goto extension */
      continue;
    }
#if FF_CODE_PAGE == 0
    if (ExCvt && c >= 0x80) { /* Is SBC extended character? */
      c = ExCvt[c - 0x80];    /* To upper SBC extended character */
    }
#elif FF_CODE_PAGE < 900
    if (c >= 0x80) {       /* Is SBC extended character? */
      c = ExCvt[c - 0x80]; /* To upper SBC extended character */
    }
#endif
    if (dbc_1st(c)) {                                         /* Check if it is a DBC 1st byte */
      d = (BYTE)p[si++];                                      /* Get 2nd byte */
      if (!dbc_2nd(d) || i >= ni - 1) return FR_INVALID_NAME; /* Reject invalid DBC */
      sfn[i++] = c;
      sfn[i++] = d;
    } else { /* SBC */
      if (chk_chr("\"*+,:;<=>\?[]|\x7F", c))
        return FR_INVALID_NAME;  /* Reject illegal chrs for SFN */
      if (IsLower(c)) c -= 0x20; /* To upper */
      sfn[i++] = c;
    }
  }
  *path = p + si;                     /* Return pointer to the next segment */
  if (i == 0) return FR_INVALID_NAME; /* Reject nul string */

  if (sfn[0] == DDEM)
    sfn[0] = RDDEM; /* If the first character collides with DDEM, replace it with RDDEM */
  sfn[NSFLAG] = (c <= ' ') ? NS_LAST : 0; /* Set last segment flag if end of the path */

  return FR_OK;
#endif /* FF_USE_LFN */
}

/*-----------------------------------------------------------------------*/
/* Follow a file path                                                    */
/*-----------------------------------------------------------------------*/

static FRESULT
follow_path(                  /* FR_OK(0): successful, !=0: error code */
            FF_DIR* dp,       /* Directory object to return last directory and found object */
            const TCHAR* path /* Full-path string to find a file or directory */
) {
  FRESULT res;
  BYTE ns;
  FATFS* fs = dp->obj.fs;

#if FF_FS_RPATH != 0
  if (*path != '/' && *path != '\\') { /* Without heading separator */
    dp->obj.sclust = fs->cdir;         /* Start from current directory */
  } else
#endif
  {                                               /* With heading separator */
    while (*path == '/' || *path == '\\') path++; /* Strip heading separator */
    dp->obj.sclust = 0;                           /* Start from root directory */
  }
#if FF_FS_EXFAT
  dp->obj.n_frag = 0; /* Invalidate last fragment counter of the object */
#if FF_FS_RPATH != 0
  if (fs->fs_type == FS_EXFAT && dp->obj.sclust) { /* exFAT: Retrieve the sub-directory's status */
    FF_DIR dj;

    dp->obj.c_scl = fs->cdc_scl;
    dp->obj.c_size = fs->cdc_size;
    dp->obj.c_ofs = fs->cdc_ofs;
    res = load_obj_xdir(&dj, &dp->obj);
    if (res != FR_OK) return res;
    dp->obj.objsize = ld_dword(fs->dirbuf + XDIR_FileSize);
    dp->obj.stat = fs->dirbuf[XDIR_GenFlags] & 2;
  }
#endif
#endif

  if ((UINT)*path < ' ') { /* Null path name is the origin directory itself */
    dp->fn[NSFLAG] = NS_NONAME;
    res = dir_sdi(dp, 0);

  } else { /* Follow path */
    for (;;) {
      res = create_name(dp, &path); /* Get a segment name of the path */
      if (res != FR_OK) break;
      res = dir_find(dp); /* Find an object with the segment name */
      ns = dp->fn[NSFLAG];
      if (res != FR_OK) {                     /* Failed to find the object */
        if (res == FR_NO_FILE) {              /* Object is not found */
          if (FF_FS_RPATH && (ns & NS_DOT)) { /* If dot entry is not exist, stay there */
            if (!(ns & NS_LAST)) continue;    /* Continue to follow if not last segment */
            dp->fn[NSFLAG] = NS_NONAME;
            res = FR_OK;
          } else {                                 /* Could not find the object */
            if (!(ns & NS_LAST)) res = FR_NO_PATH; /* Adjust error code if not last segment */
          }
        }
        break;
      }
      if (ns & NS_LAST) break; /* Last segment matched. Function completed. */
      /* Get into the sub-directory */
      if (!(dp->obj.attr & AM_DIR)) { /* It is not a sub-directory and cannot follow */
        res = FR_NO_PATH;
        break;
      }
#if FF_FS_EXFAT
      if (fs->fs_type == FS_EXFAT) { /* Save containing directory information for next dir */
        dp->obj.c_scl = dp->obj.sclust;
        dp->obj.c_size = ((DWORD)dp->obj.objsize & 0xFFFFFF00) | dp->obj.stat;
        dp->obj.c_ofs = dp->blk_ofs;
        dp->obj.sclust = ld_dword(fs->dirbuf + XDIR_FstClus); /* Open next directory */
        dp->obj.stat = fs->dirbuf[XDIR_GenFlags] & 2;
        dp->obj.objsize = ld_qword(fs->dirbuf + XDIR_FileSize);
      } else
#endif
      {
        dp->obj.sclust = ld_clust(fs, fs->win + dp->dptr % SS(fs)); /* Open next directory */
      }
    }
  }

  return res;
}

/*-----------------------------------------------------------------------*/
/* Get logical drive number from path name                               */
/*-----------------------------------------------------------------------*/

static int get_ldnumber(                   /* Returns logical drive number (-1:invalid drive) */
                        const TCHAR** path /* Pointer to pointer to the path name */
) {
  const TCHAR *tp, *tt;
  UINT i;
  int vol = -1;
#if FF_STR_VOLUME_ID /* Find string drive id */
  static const char* const volid[] = {FF_VOLUME_STRS};
  const char* sp;
  char c;
  TCHAR tc;
#endif

  if (*path) { /* If the pointer is not a null */
    for (tt = *path; (UINT)*tt >= (FF_USE_LFN ? ' ' : '!') && *tt != ':'; tt++)
      ;               /* Find a colon in the path */
    if (*tt == ':') { /* If a colon is exist in the path name */
      tp = *path;
      i = *tp++;
      if (IsDigit(i) && tp == tt) {    /* Is there a numeric drive id + colon? */
        if ((i -= '0') < FF_VOLUMES) { /* If drive id is found, get the value and strip it */
          vol = (int)i;
          *path = ++tt;
        }
      }
#if FF_STR_VOLUME_ID
      else { /* No numeric drive number, find string drive id */
        i = 0;
        tt++;
        do {
          sp = volid[i];
          tp = *path;
          do { /* Compare a string drive id with path name */
            c = *sp++;
            tc = *tp++;
            if (IsLower(tc)) tc -= 0x20;
          } while (c && (TCHAR)c == tc);
        } while ((c || tp != tt) && ++i < FF_VOLUMES); /* Repeat for each id until pattern match */
        if (i < FF_VOLUMES) { /* If a drive id is found, get the value and strip it */
          vol = (int)i;
          *path = tt;
        }
      }
#endif
    } else { /* No volume id and use default drive */
#if FF_FS_RPATH != 0 && FF_VOLUMES >= 2
      vol = CurrVol; /* Current drive */
#else
      vol = 0; /* Drive 0 */
#endif
    }
  }
  return vol;
}

/*-----------------------------------------------------------------------*/
/* Load a sector and check if it is an FAT VBR                           */
/*-----------------------------------------------------------------------*/

static BYTE check_fs(/* 0:FAT, 1:exFAT, 2:Valid BS but not FAT, 3:Not a BS, 4:Disk error */
                     FATFS* fs, /* Filesystem object */
                     DWORD sect /* Sector# (lba) to load and check if it is an FAT-VBR or not */
) {
  fs->wflag = 0;
  fs->winsect = 0xFFFFFFFF;                     /* Invaidate window */
  if (move_window(fs, sect) != FR_OK) return 4; /* Load boot record */

  if (ld_word(fs->win + BS_55AA) != 0xAA55)
    return 3; /* Check boot record signature (always placed here even if the sector size is >512) */

#if FF_FS_EXFAT
  if (!mem_cmp(fs->win + BS_JmpBoot,
               "\xEB\x76\x90"
               "EXFAT   ",
               11))
    return 1; /* Check if exFAT VBR */
#endif
  if (fs->win[BS_JmpBoot] == 0xE9 ||
      (fs->win[BS_JmpBoot] == 0xEB && fs->win[BS_JmpBoot + 2] == 0x90)) { /* Valid JumpBoot code? */
    if (!mem_cmp(fs->win + BS_FilSysType, "FAT", 3)) return 0;            /* Is it an FAT VBR? */
    if (!mem_cmp(fs->win + BS_FilSysType32, "FAT32", 5)) return 0;        /* Is it an FAT32 VBR? */
  }
  return 2; /* Valid BS but not FAT */
}

/*-----------------------------------------------------------------------*/
/* Find logical drive and check if the volume is mounted                 */
/*-----------------------------------------------------------------------*/

static FRESULT
find_volume(                    /* FR_OK(0): successful, !=0: any error occurred */
            const TCHAR** path, /* Pointer to pointer to the path name (drive number) */
            FATFS** rfs,        /* Pointer to pointer to the found filesystem object */
            BYTE mode           /* !=0: Check write protection for write access */
) {
  BYTE fmt, *pt;
  int vol;
  DSTATUS stat;
  DWORD bsect, fasize, tsect, sysect, nclst, szbfat, br[4];
  WORD nrsv;
  FATFS* fs;
  UINT i;

  /* Get logical drive number */
  *rfs = 0;
  vol = get_ldnumber(path);
  if (vol < 0) return FR_INVALID_DRIVE;

  /* Check if the filesystem object is valid or not */
  fs = FatFs[vol];                /* Get pointer to the filesystem object */
  if (!fs) return FR_NOT_ENABLED; /* Is the filesystem object available? */
#if FF_FS_REENTRANT
  if (!lock_fs(fs)) return FR_TIMEOUT; /* Lock the volume */
#endif
  *rfs = fs; /* Return pointer to the filesystem object */

  mode &= (BYTE)~FA_READ; /* Desired access mode, write access or not */
  if (fs->fs_type != 0) { /* If the volume has been mounted */
    stat = disk_status(fs->pdrv);
    if (!(stat & STA_NOINIT)) { /* and the physical drive is kept initialized */
      if (!FF_FS_READONLY && mode && (stat & STA_PROTECT)) { /* Check write protection if needed */
        return FR_WRITE_PROTECTED;
      }
      return FR_OK; /* The filesystem object is valid */
    }
  }

  /* The filesystem object is not valid. */
  /* Following code attempts to mount the volume. (analyze BPB and initialize the filesystem object) */

  fs->fs_type = 0;                  /* Clear the filesystem object */
  fs->pdrv = LD2PD(vol);            /* Bind the logical drive and a physical drive */
  stat = disk_initialize(fs->pdrv); /* Initialize the physical drive */
  if (stat & STA_NOINIT) {          /* Check if the initialization succeeded */
    return FR_NOT_READY;            /* Failed to initialize due to no medium or hard error */
  }
  if (!FF_FS_READONLY && mode && (stat & STA_PROTECT)) { /* Check disk write protection if needed */
    return FR_WRITE_PROTECTED;
  }
#if FF_MAX_SS != FF_MIN_SS /* Get sector size (multiple sector size cfg only) */
  if (disk_ioctl(fs->pdrv, GET_SECTOR_SIZE, &SS(fs)) != RES_OK) return FR_DISK_ERR;
  if (SS(fs) > FF_MAX_SS || SS(fs) < FF_MIN_SS || (SS(fs) & (SS(fs) - 1))) return FR_DISK_ERR;
#endif

  /* Find an FAT partition on the drive. Supports only generic partitioning rules, FDISK and SFD. */
  bsect = 0;
  fmt = check_fs(fs, bsect); /* Load sector 0 and check if it is an FAT-VBR as SFD */
  if (fmt == 2 || (fmt < 2 && LD2PT(vol) != 0)) { /* Not an FAT-VBR or forced partition number */
    for (i = 0; i < 4; i++) {                     /* Get partition offset */
      pt = fs->win + (MBR_Table + i * SZ_PTE);
      br[i] = pt[PTE_System] ? ld_dword(pt + PTE_StLba) : 0;
    }
    i = LD2PT(vol); /* Partition number: 0:auto, 1-4:forced */
    if (i != 0) i--;
    do { /* Find an FAT volume */
      bsect = br[i];
      fmt = bsect ? check_fs(fs, bsect) : 3; /* Check the partition */
    } while (LD2PT(vol) == 0 && fmt >= 2 && ++i < 4);
  }
  if (fmt == 4) return FR_DISK_ERR;      /* An error occured in the disk I/O layer */
  if (fmt >= 2) return FR_NO_FILESYSTEM; /* No FAT volume is found */

    /* An FAT volume is found (bsect). Following code initializes the filesystem object */

#if FF_FS_EXFAT
  if (fmt == 1) {
    QWORD maxlba;

    for (i = BPB_ZeroedEx; i < BPB_ZeroedEx + 53 && fs->win[i] == 0; i++)
      ; /* Check zero filler */
    if (i < BPB_ZeroedEx + 53) return FR_NO_FILESYSTEM;

    if (ld_word(fs->win + BPB_FSVerEx) != 0x100)
      return FR_NO_FILESYSTEM; /* Check exFAT version (must be version 1.0) */

    if (1 << fs->win[BPB_BytsPerSecEx] !=
        SS(fs)) { /* (BPB_BytsPerSecEx must be equal to the physical sector size) */
      return FR_NO_FILESYSTEM;
    }

    maxlba = ld_qword(fs->win + BPB_TotSecEx) + bsect;  /* Last LBA + 1 of the volume */
    if (maxlba >= 0x100000000) return FR_NO_FILESYSTEM; /* (It cannot be handled in 32-bit LBA) */

    fs->fsize = ld_dword(fs->win + BPB_FatSzEx); /* Number of sectors per FAT */

    fs->n_fats = fs->win[BPB_NumFATsEx];          /* Number of FATs */
    if (fs->n_fats != 1) return FR_NO_FILESYSTEM; /* (Supports only 1 FAT) */

    fs->csize = 1 << fs->win[BPB_SecPerClusEx];  /* Cluster size */
    if (fs->csize == 0) return FR_NO_FILESYSTEM; /* (Must be 1..32768) */

    nclst = ld_dword(fs->win + BPB_NumClusEx);      /* Number of clusters */
    if (nclst > MAX_EXFAT) return FR_NO_FILESYSTEM; /* (Too many clusters) */
    fs->n_fatent = nclst + 2;

    /* Boundaries and Limits */
    fs->volbase = bsect;
    fs->database = bsect + ld_dword(fs->win + BPB_DataOfsEx);
    fs->fatbase = bsect + ld_dword(fs->win + BPB_FatOfsEx);
    if (maxlba < (QWORD)fs->database + nclst * fs->csize)
      return FR_NO_FILESYSTEM; /* (Volume size must not be smaller than the size requiered) */
    fs->dirbase = ld_dword(fs->win + BPB_RootClusEx);

    /* Check if bitmap location is in assumption (at the first cluster) */
    if (move_window(fs, clst2sect(fs, fs->dirbase)) != FR_OK) return FR_DISK_ERR;
    for (i = 0; i < SS(fs); i += SZDIRE) {
      if (fs->win[i] == 0x81 && ld_dword(fs->win + i + 20) == 2)
        break; /* 81 entry with cluster #2? */
    }
    if (i == SS(fs)) return FR_NO_FILESYSTEM;
#if !FF_FS_READONLY
    fs->last_clst = fs->free_clst = 0xFFFFFFFF; /* Initialize cluster allocation information */
#endif
    fmt = FS_EXFAT; /* FAT sub-type */
  } else
#endif /* FF_FS_EXFAT */
  {
    if (ld_word(fs->win + BPB_BytsPerSec) != SS(fs))
      return FR_NO_FILESYSTEM; /* (BPB_BytsPerSec must be equal to the physical sector size) */

    fasize = ld_word(fs->win + BPB_FATSz16); /* Number of sectors per FAT */
    if (fasize == 0) fasize = ld_dword(fs->win + BPB_FATSz32);
    fs->fsize = fasize;

    fs->n_fats = fs->win[BPB_NumFATs];                               /* Number of FATs */
    if (fs->n_fats != 1 && fs->n_fats != 2) return FR_NO_FILESYSTEM; /* (Must be 1 or 2) */
    fasize *= fs->n_fats; /* Number of sectors for FAT area */

    fs->csize = fs->win[BPB_SecPerClus]; /* Cluster size */
    if (fs->csize == 0 || (fs->csize & (fs->csize - 1)))
      return FR_NO_FILESYSTEM; /* (Must be power of 2) */

    fs->n_rootdir = ld_word(fs->win + BPB_RootEntCnt); /* Number of root directory entries */
    if (fs->n_rootdir % (SS(fs) / SZDIRE)) return FR_NO_FILESYSTEM; /* (Must be sector aligned) */

    tsect = ld_word(fs->win + BPB_TotSec16); /* Number of sectors on the volume */
    if (tsect == 0) tsect = ld_dword(fs->win + BPB_TotSec32);

    nrsv = ld_word(fs->win + BPB_RsvdSecCnt); /* Number of reserved sectors */
    if (nrsv == 0) return FR_NO_FILESYSTEM;   /* (Must not be 0) */

    /* Determine the FAT sub type */
    sysect = nrsv + fasize + fs->n_rootdir / (SS(fs) / SZDIRE); /* RSV + FAT + DIR */
    if (tsect < sysect) return FR_NO_FILESYSTEM;                /* (Invalid volume size) */
    nclst = (tsect - sysect) / fs->csize;                       /* Number of clusters */
    if (nclst == 0) return FR_NO_FILESYSTEM;                    /* (Invalid volume size) */
    fmt = 0;
    if (nclst <= MAX_FAT32) fmt = FS_FAT32;
    if (nclst <= MAX_FAT16) fmt = FS_FAT16;
    if (nclst <= MAX_FAT12) fmt = FS_FAT12;
    if (fmt == 0) return FR_NO_FILESYSTEM;

    /* Boundaries and Limits */
    fs->n_fatent = nclst + 2;      /* Number of FAT entries */
    fs->volbase = bsect;           /* Volume start sector */
    fs->fatbase = bsect + nrsv;    /* FAT start sector */
    fs->database = bsect + sysect; /* Data start sector */
    if (fmt == FS_FAT32) {
      if (ld_word(fs->win + BPB_FSVer32) != 0)
        return FR_NO_FILESYSTEM;                        /* (Must be FAT32 revision 0.0) */
      if (fs->n_rootdir != 0) return FR_NO_FILESYSTEM;  /* (BPB_RootEntCnt must be 0) */
      fs->dirbase = ld_dword(fs->win + BPB_RootClus32); /* Root directory start cluster */
      szbfat = fs->n_fatent * 4;                        /* (Needed FAT size) */
    } else {
      if (fs->n_rootdir == 0) return FR_NO_FILESYSTEM; /* (BPB_RootEntCnt must not be 0) */
      fs->dirbase = fs->fatbase + fasize;              /* Root directory start sector */
      szbfat = (fmt == FS_FAT16) ?                     /* (Needed FAT size) */
                   fs->n_fatent * 2
                                 : fs->n_fatent * 3 / 2 + (fs->n_fatent & 1);
    }
    if (fs->fsize < (szbfat + (SS(fs) - 1)) / SS(fs))
      return FR_NO_FILESYSTEM; /* (BPB_FATSz must not be less than the size needed) */

#if !FF_FS_READONLY
    /* Get FSInfo if available */
    fs->last_clst = fs->free_clst = 0xFFFFFFFF; /* Initialize cluster allocation information */
    fs->fsi_flag = 0x80;
#if (FF_FS_NOFSINFO & 3) != 3
    if (fmt == FS_FAT32 /* Allow to update FSInfo only if BPB_FSInfo32 == 1 */
        && ld_word(fs->win + BPB_FSInfo32) == 1 && move_window(fs, bsect + 1) == FR_OK) {
      fs->fsi_flag = 0;
      if (ld_word(fs->win + BS_55AA) == 0xAA55 /* Load FSInfo data if available */
          && ld_dword(fs->win + FSI_LeadSig) == 0x41615252 &&
          ld_dword(fs->win + FSI_StrucSig) == 0x61417272) {
#if (FF_FS_NOFSINFO & 1) == 0
        fs->free_clst = ld_dword(fs->win + FSI_Free_Count);
#endif
#if (FF_FS_NOFSINFO & 2) == 0
        fs->last_clst = ld_dword(fs->win + FSI_Nxt_Free);
#endif
      }
    }
#endif /* (FF_FS_NOFSINFO & 3) != 3 */
#endif /* !FF_FS_READONLY */
  }

  fs->fs_type = fmt; /* FAT sub-type */
  fs->id = ++Fsid;   /* Volume mount ID */
#if FF_USE_LFN == 1
  fs->lfnbuf = LfnBuf; /* Static LFN working buffer */
#if FF_FS_EXFAT
  fs->dirbuf = DirBuf; /* Static directory block scratchpad buuffer */
#endif
#endif
#if FF_FS_RPATH != 0
  fs->cdir = 0; /* Initialize current directory */
#endif
#if FF_FS_LOCK != 0 /* Clear file lock semaphores */
  clear_lock(fs);
#endif
  return FR_OK;
}

/*-----------------------------------------------------------------------*/
/* Check if the file/directory object is valid or not                    */
/*-----------------------------------------------------------------------*/

static FRESULT
validate(/* Returns FR_OK or FR_INVALID_OBJECT */
         FFOBJID*
             obj, /* Pointer to the FFOBJID, the 1st member in the FIL/DIR object, to check validity */
         FATFS** rfs /* Pointer to pointer to the owner filesystem object to return */
) {
  FRESULT res = FR_INVALID_OBJECT;

  if (obj && obj->fs && obj->fs->fs_type &&
      obj->id == obj->fs->id) { /* Test if the object is valid */
#if FF_FS_REENTRANT
    if (lock_fs(obj->fs)) { /* Obtain the filesystem object */
      if (!(disk_status(obj->fs->pdrv) &
            STA_NOINIT)) { /* Test if the phsical drive is kept initialized */
        res = FR_OK;
      } else {
        unlock_fs(obj->fs, FR_OK);
      }
    } else {
      res = FR_TIMEOUT;
    }
#else
    if (!(disk_status(obj->fs->pdrv) &
          STA_NOINIT)) { /* Test if the phsical drive is kept initialized */
      res = FR_OK;
    }
#endif
  }
  *rfs = (res == FR_OK) ? obj->fs : 0; /* Corresponding filesystem object */
  return res;
}

/*---------------------------------------------------------------------------

   Public Functions (FatFs API)

----------------------------------------------------------------------------*/

/*-----------------------------------------------------------------------*/
/* Mount/Unmount a Logical Drive                                         */
/*-----------------------------------------------------------------------*/

FRESULT f_mount(FATFS* fs,         /* Pointer to the filesystem object (NULL:unmount)*/
                const TCHAR* path, /* Logical drive number to be mounted/unmounted */
                BYTE opt /* Mode option 0:Do not mount (delayed mount), 1:Mount immediately */
) {
  FATFS* cfs;
  int vol;
  FRESULT res;
  const TCHAR* rp = path;

  /* Get logical drive number */
  vol = get_ldnumber(&rp);
  if (vol < 0) return FR_INVALID_DRIVE;
  cfs = FatFs[vol]; /* Pointer to fs object */

  if (cfs) {
#if FF_FS_LOCK != 0
    clear_lock(cfs);
#endif
#if FF_FS_REENTRANT /* Discard sync object of the current volume */
    if (!ff_del_syncobj(cfs->sobj)) return FR_INT_ERR;
#endif
    cfs->fs_type = 0; /* Clear old fs object */
  }

  if (fs) {
    fs->fs_type = 0; /* Clear new fs object */
#if FF_FS_REENTRANT  /* Create sync object for the new volume */
    if (!ff_cre_syncobj((BYTE)vol, &fs->sobj)) return FR_INT_ERR;
#endif
  }
  FatFs[vol] = fs; /* Register new fs object */

  if (opt == 0) return FR_OK; /* Do not mount now, it will be mounted later */

  res = find_volume(&path, &fs, 0); /* Force mounted the volume */
  if (res != FR_OK) {
    FatFs[vol] = NULL;
  }

  LEAVE_FF(fs, res);
}

/*-----------------------------------------------------------------------*/
/* Open or Create a File                                                 */
/*-----------------------------------------------------------------------*/

FRESULT f_open(FIL* fp,           /* Pointer to the blank file object */
               const TCHAR* path, /* Pointer to the file name */
               BYTE mode          /* Access mode and file open mode flags */
) {
  FRESULT res;
  FF_DIR dj;
  FATFS* fs;
#if !FF_FS_READONLY
  DWORD dw, cl, bcs, clst, sc;
  FSIZE_t ofs;
#endif
  DEF_NAMBUF

  if (!fp) return FR_INVALID_OBJECT;

  /* Get logical drive */
  mode &= FF_FS_READONLY ? FA_READ
                         : FA_READ | FA_WRITE | FA_CREATE_ALWAYS | FA_CREATE_NEW | FA_OPEN_ALWAYS |
                               FA_OPEN_APPEND | FA_SEEKEND;
  res = find_volume(&path, &fs, mode);
  if (res == FR_OK) {
    dj.obj.fs = fs;
    INIT_NAMBUF(fs);
    res = follow_path(&dj, path); /* Follow the file path */
#if !FF_FS_READONLY               /* Read/Write configuration */
    if (res == FR_OK) {
      if (dj.fn[NSFLAG] & NS_NONAME) { /* Origin directory itself? */
        res = FR_INVALID_NAME;
      }
#if FF_FS_LOCK != 0
      else {
        res = chk_lock(&dj, (mode & ~FA_READ) ? 1 : 0); /* Check if the file can be used */
      }
#endif
    }
    /* Create or Open a file */
    if (mode & (FA_CREATE_ALWAYS | FA_OPEN_ALWAYS | FA_CREATE_NEW)) {
      if (res != FR_OK) {        /* No file, create new */
        if (res == FR_NO_FILE) { /* There is no file to open, create a new entry */
#if FF_FS_LOCK != 0
          res = enq_lock() ? dir_register(&dj) : FR_TOO_MANY_OPEN_FILES;
#else
          res = dir_register(&dj);
#endif
        }
        mode |= FA_CREATE_ALWAYS; /* File is created */
      } else {                    /* Any object with the same name is already existing */
        if (dj.obj.attr & (AM_RDO | AM_DIR)) { /* Cannot overwrite it (R/O or DIR) */
          res = FR_DENIED;
        } else {
          if (mode & FA_CREATE_NEW) res = FR_EXIST; /* Cannot create as new file */
        }
      }
      if (res == FR_OK && (mode & FA_CREATE_ALWAYS)) { /* Truncate the file if overwrite mode */
#if FF_FS_EXFAT
        if (fs->fs_type == FS_EXFAT) {
          /* Get current allocation info */
          fp->obj.fs = fs;
          fp->obj.sclust = cl = ld_dword(fs->dirbuf + XDIR_FstClus);
          fp->obj.objsize = ld_qword(fs->dirbuf + XDIR_FileSize);
          fp->obj.stat = fs->dirbuf[XDIR_GenFlags] & 2;
          fp->obj.n_frag = 0;
          /* Set directory entry block initial state */
          mem_set(fs->dirbuf + 2, 0, 30);  /* Clear 85 entry except for NumSec */
          mem_set(fs->dirbuf + 38, 0, 26); /* Clear C0 entry except for NumName and NameHash */
          fs->dirbuf[XDIR_Attr] = AM_ARC;
          st_dword(fs->dirbuf + XDIR_CrtTime, GET_FATTIME());
          fs->dirbuf[XDIR_GenFlags] = 1;
          res = store_xdir(&dj);
          if (res == FR_OK && cl != 0) { /* Remove the cluster chain if exist */
            res = remove_chain(&fp->obj, cl, 0);
            fs->last_clst = cl - 1; /* Reuse the cluster hole */
          }
        } else
#endif
        {
          /* Set directory entry initial state */
          cl = ld_clust(fs, dj.dir);                     /* Get current cluster chain */
          st_dword(dj.dir + DIR_CrtTime, GET_FATTIME()); /* Set created time */
          dj.dir[DIR_Attr] = AM_ARC;                     /* Reset attribute */
          st_clust(fs, dj.dir, 0);                       /* Reset file allocation info */
          st_dword(dj.dir + DIR_FileSize, 0);
          fs->wflag = 1;
          if (cl != 0) { /* Remove the cluster chain if exist */
            dw = fs->winsect;
            res = remove_chain(&dj.obj, cl, 0);
            if (res == FR_OK) {
              res = move_window(fs, dw);
              fs->last_clst = cl - 1; /* Reuse the cluster hole */
            }
          }
        }
      }
    } else {                        /* Open an existing file */
      if (res == FR_OK) {           /* Is the object exsiting? */
        if (dj.obj.attr & AM_DIR) { /* File open against a directory */
          res = FR_NO_FILE;
        } else {
          if ((mode & FA_WRITE) && (dj.obj.attr & AM_RDO)) { /* Write mode open against R/O file */
            res = FR_DENIED;
          }
        }
      }
    }
    if (res == FR_OK) {
      if (mode & FA_CREATE_ALWAYS)
        mode |= FA_MODIFIED;      /* Set file change flag if created or overwritten */
      fp->dir_sect = fs->winsect; /* Pointer to the directory entry */
      fp->dir_ptr = dj.dir;
#if FF_FS_LOCK != 0
      fp->obj.lockid =
          inc_lock(&dj, (mode & ~FA_READ) ? 1 : 0); /* Lock the file for this session */
      if (!fp->obj.lockid) res = FR_INT_ERR;
#endif
    }
#else /* R/O configuration */
    if (res == FR_OK) {
      if (dj.fn[NSFLAG] & NS_NONAME) { /* Is it origin directory itself? */
        res = FR_INVALID_NAME;
      } else {
        if (dj.obj.attr & AM_DIR) { /* Is it a directory? */
          res = FR_NO_FILE;
        }
      }
    }
#endif

    if (res == FR_OK) {
#if FF_FS_EXFAT
      if (fs->fs_type == FS_EXFAT) {
        fp->obj.c_scl = dj.obj.sclust; /* Get containing directory info */
        fp->obj.c_size = ((DWORD)dj.obj.objsize & 0xFFFFFF00) | dj.obj.stat;
        fp->obj.c_ofs = dj.blk_ofs;
        fp->obj.sclust = ld_dword(fs->dirbuf + XDIR_FstClus); /* Get object allocation info */
        fp->obj.objsize = ld_qword(fs->dirbuf + XDIR_FileSize);
        fp->obj.stat = fs->dirbuf[XDIR_GenFlags] & 2;
        fp->obj.n_frag = 0;
      } else
#endif
      {
        fp->obj.sclust = ld_clust(fs, dj.dir); /* Get object allocation info */
        fp->obj.objsize = ld_dword(dj.dir + DIR_FileSize);
      }
#if FF_USE_FASTSEEK
      fp->cltbl = 0; /* Disable fast seek mode */
#endif
      fp->obj.fs = fs; /* Validate the file object */
      fp->obj.id = fs->id;
      fp->flag = mode; /* Set file access mode */
      fp->err = 0;     /* Clear error flag */
      fp->sect = 0;    /* Invalidate current data sector */
      fp->fptr = 0;    /* Set file pointer top of the file */
#if !FF_FS_READONLY
#if !FF_FS_TINY
      mem_set(fp->buf, 0, FF_MAX_SS); /* Clear sector buffer */
#endif
      if ((mode & FA_SEEKEND) &&
          fp->obj.objsize > 0) {         /* Seek to end of file if FA_OPEN_APPEND is specified */
        fp->fptr = fp->obj.objsize;      /* Offset to seek */
        bcs = (DWORD)fs->csize * SS(fs); /* Cluster size in byte */
        clst = fp->obj.sclust;           /* Follow the cluster chain */
        for (ofs = fp->obj.objsize; res == FR_OK && ofs > bcs; ofs -= bcs) {
          clst = get_fat(&fp->obj, clst);
          if (clst <= 1) res = FR_INT_ERR;
          if (clst == 0xFFFFFFFF) res = FR_DISK_ERR;
        }
        fp->clust = clst;
        if (res == FR_OK && ofs % SS(fs)) { /* Fill sector buffer if not on the sector boundary */
          if ((sc = clst2sect(fs, clst)) == 0) {
            res = FR_INT_ERR;
          } else {
            fp->sect = sc + (DWORD)(ofs / SS(fs));
#if !FF_FS_TINY
            if (disk_read(fs->pdrv, fp->buf, fp->sect, 1) != RES_OK) res = FR_DISK_ERR;
#endif
          }
        }
      }
#endif
    }

    FREE_NAMBUF();
  }

  if (res != FR_OK) fp->obj.fs = 0; /* Invalidate file object on error */

  LEAVE_FF(fs, res);
}

/*-----------------------------------------------------------------------*/
/* Read File                                                             */
/*-----------------------------------------------------------------------*/

FRESULT f_read(FIL* fp,    /* Pointer to the file object */
               void* buff, /* Pointer to data buffer */
               UINT btr,   /* Number of bytes to read */
               UINT* br    /* Pointer to number of bytes read */
) {
  FRESULT res;
  FATFS* fs;
  DWORD clst, sect;
  FSIZE_t remain;
  UINT rcnt, cc, csect;
  BYTE* rbuff = (BYTE*)buff;

  *br = 0;                       /* Clear read byte counter */
  res = validate(&fp->obj, &fs); /* Check validity of the file object */
  if (res != FR_OK || (res = (FRESULT)fp->err) != FR_OK) LEAVE_FF(fs, res); /* Check validity */
  if (!(fp->flag & FA_READ)) LEAVE_FF(fs, FR_DENIED);                       /* Check access mode */
  remain = fp->obj.objsize - fp->fptr;
  if (btr > remain) btr = (UINT)remain; /* Truncate btr by remaining bytes */

  for (; btr; /* Repeat until all data read */
       btr -= rcnt, *br += rcnt, rbuff += rcnt, fp->fptr += rcnt) {
    if (fp->fptr % SS(fs) == 0) {                          /* On the sector boundary? */
      csect = (UINT)(fp->fptr / SS(fs) & (fs->csize - 1)); /* Sector offset in the cluster */
      if (csect == 0) {                                    /* On the cluster boundary? */
        if (fp->fptr == 0) {                               /* On the top of the file? */
          clst = fp->obj.sclust; /* Follow cluster chain from the origin */
        } else {                 /* Middle or end of the file */
#if FF_USE_FASTSEEK
          if (fp->cltbl) {
            clst = clmt_clust(fp, fp->fptr); /* Get cluster# from the CLMT */
          } else
#endif
          {
            clst = get_fat(&fp->obj, fp->clust); /* Follow cluster chain on the FAT */
          }
        }
        if (clst < 2) ABORT(fs, FR_INT_ERR);
        if (clst == 0xFFFFFFFF) ABORT(fs, FR_DISK_ERR);
        fp->clust = clst; /* Update current cluster */
      }
      sect = clst2sect(fs, fp->clust); /* Get current sector */
      if (sect == 0) ABORT(fs, FR_INT_ERR);
      sect += csect;
      cc = btr / SS(fs);              /* When remaining bytes >= sector size, */
      if (cc > 0) {                   /* Read maximum contiguous sectors directly */
        if (csect + cc > fs->csize) { /* Clip at cluster boundary */
          cc = fs->csize - csect;
        }
        if (disk_read(fs->pdrv, rbuff, sect, cc) != RES_OK) ABORT(fs, FR_DISK_ERR);
#if !FF_FS_READONLY && \
    FF_FS_MINIMIZE <=  \
        2 /* Replace one of the read sectors with cached data if it contains a dirty sector */
#if FF_FS_TINY
        if (fs->wflag && fs->winsect - sect < cc) {
          mem_cpy(rbuff + ((fs->winsect - sect) * SS(fs)), fs->win, SS(fs));
        }
#else
        if ((fp->flag & FA_DIRTY) && fp->sect - sect < cc) {
          mem_cpy(rbuff + ((fp->sect - sect) * SS(fs)), fp->buf, SS(fs));
        }
#endif
#endif
        rcnt = SS(fs) * cc; /* Number of bytes transferred */
        continue;
      }
#if !FF_FS_TINY
      if (fp->sect != sect) { /* Load data sector if not in cache */
#if !FF_FS_READONLY
        if (fp->flag & FA_DIRTY) { /* Write-back dirty sector cache */
          if (disk_write(fs->pdrv, fp->buf, fp->sect, 1) != RES_OK) ABORT(fs, FR_DISK_ERR);
          fp->flag &= (BYTE)~FA_DIRTY;
        }
#endif
        if (disk_read(fs->pdrv, fp->buf, sect, 1) != RES_OK)
          ABORT(fs, FR_DISK_ERR); /* Fill sector cache */
      }
#endif
      fp->sect = sect;
    }
    rcnt = SS(fs) - (UINT)fp->fptr % SS(fs); /* Number of bytes left in the sector */
    if (rcnt > btr) rcnt = btr;              /* Clip it by btr if needed */
#if FF_FS_TINY
    if (move_window(fs, fp->sect) != FR_OK) ABORT(fs, FR_DISK_ERR); /* Move sector window */
    mem_cpy(rbuff, fs->win + fp->fptr % SS(fs), rcnt);              /* Extract partial sector */
#else
    mem_cpy(rbuff, fp->buf + fp->fptr % SS(fs), rcnt); /* Extract partial sector */
#endif
  }

  LEAVE_FF(fs, FR_OK);
}

#if !FF_FS_READONLY
/*-----------------------------------------------------------------------*/
/* Write File                                                            */
/*-----------------------------------------------------------------------*/

FRESULT f_write(FIL* fp,          /* Pointer to the file object */
                const void* buff, /* Pointer to the data to be written */
                UINT btw,         /* Number of bytes to write */
                UINT* bw          /* Pointer to number of bytes written */
) {
  FRESULT res;
  FATFS* fs;
  DWORD clst, sect;
  UINT wcnt, cc, csect;
  const BYTE* wbuff = (const BYTE*)buff;

  *bw = 0;                       /* Clear write byte counter */
  res = validate(&fp->obj, &fs); /* Check validity of the file object */
  if (res != FR_OK || (res = (FRESULT)fp->err) != FR_OK) LEAVE_FF(fs, res); /* Check validity */
  if (!(fp->flag & FA_WRITE)) LEAVE_FF(fs, FR_DENIED);                      /* Check access mode */

  /* Check fptr wrap-around (file size cannot reach 4 GiB at FAT volume) */
  if ((!FF_FS_EXFAT || fs->fs_type != FS_EXFAT) && (DWORD)(fp->fptr + btw) < (DWORD)fp->fptr) {
    btw = (UINT)(0xFFFFFFFF - (DWORD)fp->fptr);
  }

  for (; btw; /* Repeat until all data written */
       btw -= wcnt, *bw += wcnt, wbuff += wcnt, fp->fptr += wcnt,
       fp->obj.objsize = (fp->fptr > fp->obj.objsize) ? fp->fptr : fp->obj.objsize) {
    if (fp->fptr % SS(fs) == 0) {                          /* On the sector boundary? */
      csect = (UINT)(fp->fptr / SS(fs)) & (fs->csize - 1); /* Sector offset in the cluster */
      if (csect == 0) {                                    /* On the cluster boundary? */
        if (fp->fptr == 0) {                               /* On the top of the file? */
          clst = fp->obj.sclust;                           /* Follow from the origin */
          if (clst == 0) {                                 /* If no cluster is allocated, */
            clst = create_chain(&fp->obj, 0);              /* create a new cluster chain */
          }
        } else { /* On the middle or end of the file */
#if FF_USE_FASTSEEK
          if (fp->cltbl) {
            clst = clmt_clust(fp, fp->fptr); /* Get cluster# from the CLMT */
          } else
#endif
          {
            clst =
                create_chain(&fp->obj, fp->clust); /* Follow or stretch cluster chain on the FAT */
          }
        }
        if (clst == 0) break; /* Could not allocate a new cluster (disk full) */
        if (clst == 1) ABORT(fs, FR_INT_ERR);
        if (clst == 0xFFFFFFFF) ABORT(fs, FR_DISK_ERR);
        fp->clust = clst;                               /* Update current cluster */
        if (fp->obj.sclust == 0) fp->obj.sclust = clst; /* Set start cluster if the first write */
      }
#if FF_FS_TINY
      if (fs->winsect == fp->sect && sync_window(fs) != FR_OK)
        ABORT(fs, FR_DISK_ERR); /* Write-back sector cache */
#else
      if (fp->flag & FA_DIRTY) { /* Write-back sector cache */
        if (disk_write(fs->pdrv, fp->buf, fp->sect, 1) != RES_OK) ABORT(fs, FR_DISK_ERR);
        fp->flag &= (BYTE)~FA_DIRTY;
      }
#endif
      sect = clst2sect(fs, fp->clust); /* Get current sector */
      if (sect == 0) ABORT(fs, FR_INT_ERR);
      sect += csect;
      cc = btw / SS(fs);              /* When remaining bytes >= sector size, */
      if (cc > 0) {                   /* Write maximum contiguous sectors directly */
        if (csect + cc > fs->csize) { /* Clip at cluster boundary */
          cc = fs->csize - csect;
        }
        if (disk_write(fs->pdrv, wbuff, sect, cc) != RES_OK) ABORT(fs, FR_DISK_ERR);
#if FF_FS_MINIMIZE <= 2
#if FF_FS_TINY
        if (fs->winsect - sect <
            cc) { /* Refill sector cache if it gets invalidated by the direct write */
          mem_cpy(fs->win, wbuff + ((fs->winsect - sect) * SS(fs)), SS(fs));
          fs->wflag = 0;
        }
#else
        if (fp->sect - sect <
            cc) { /* Refill sector cache if it gets invalidated by the direct write */
          mem_cpy(fp->buf, wbuff + ((fp->sect - sect) * SS(fs)), SS(fs));
          fp->flag &= (BYTE)~FA_DIRTY;
        }
#endif
#endif
        wcnt = SS(fs) * cc; /* Number of bytes transferred */
        continue;
      }
#if FF_FS_TINY
      if (fp->fptr >= fp->obj.objsize) { /* Avoid silly cache filling on the growing edge */
        if (sync_window(fs) != FR_OK) ABORT(fs, FR_DISK_ERR);
        fs->winsect = sect;
      }
#else
      if (fp->sect != sect && /* Fill sector cache with file data */
          fp->fptr < fp->obj.objsize && disk_read(fs->pdrv, fp->buf, sect, 1) != RES_OK) {
        ABORT(fs, FR_DISK_ERR);
      }
#endif
      fp->sect = sect;
    }
    wcnt = SS(fs) - (UINT)fp->fptr % SS(fs); /* Number of bytes left in the sector */
    if (wcnt > btw) wcnt = btw;              /* Clip it by btw if needed */
#if FF_FS_TINY
    if (move_window(fs, fp->sect) != FR_OK) ABORT(fs, FR_DISK_ERR); /* Move sector window */
    mem_cpy(fs->win + fp->fptr % SS(fs), wbuff, wcnt);              /* Fit data to the sector */
    fs->wflag = 1;
#else
    mem_cpy(fp->buf + fp->fptr % SS(fs), wbuff, wcnt); /* Fit data to the sector */
    fp->flag |= FA_DIRTY;
#endif
  }

  fp->flag |= FA_MODIFIED; /* Set file change flag */

  LEAVE_FF(fs, FR_OK);
}

/*-----------------------------------------------------------------------*/
/* Synchronize the File                                                  */
/*-----------------------------------------------------------------------*/

FRESULT f_sync(FIL* fp /* Pointer to the file object */
) {
  FRESULT res;
  FATFS* fs;
  DWORD tm;
  BYTE* dir;

  res = validate(&fp->obj, &fs); /* Check validity of the file object */
  if (res == FR_OK) {
    if (fp->flag & FA_MODIFIED) { /* Is there any change to the file? */
#if !FF_FS_TINY
      if (fp->flag & FA_DIRTY) { /* Write-back cached data if needed */
        if (disk_write(fs->pdrv, fp->buf, fp->sect, 1) != RES_OK) LEAVE_FF(fs, FR_DISK_ERR);
        fp->flag &= (BYTE)~FA_DIRTY;
      }
#endif
      /* Update the directory entry */
      tm = GET_FATTIME(); /* Modified time */
#if FF_FS_EXFAT
      if (fs->fs_type == FS_EXFAT) {
        res = fill_first_frag(&fp->obj); /* Fill first fragment on the FAT if needed */
        if (res == FR_OK) {
          res = fill_last_frag(&fp->obj, fp->clust,
                               0xFFFFFFFF); /* Fill last fragment on the FAT if needed */
        }
        if (res == FR_OK) {
          FF_DIR dj;
          DEF_NAMBUF

          INIT_NAMBUF(fs);
          res = load_obj_xdir(&dj, &fp->obj); /* Load directory entry block */
          if (res == FR_OK) {
            fs->dirbuf[XDIR_Attr] |=
                AM_ARC; /* Set archive attribute to indicate that the file has been changed */
            fs->dirbuf[XDIR_GenFlags] = fp->obj.stat | 1; /* Update file allocation information */
            st_dword(fs->dirbuf + XDIR_FstClus, fp->obj.sclust);
            st_qword(fs->dirbuf + XDIR_FileSize, fp->obj.objsize);
            st_qword(fs->dirbuf + XDIR_ValidFileSize, fp->obj.objsize);
            st_dword(fs->dirbuf + XDIR_ModTime, tm); /* Update modified time */
            fs->dirbuf[XDIR_ModTime10] = 0;
            st_dword(fs->dirbuf + XDIR_AccTime, 0);
            res = store_xdir(&dj); /* Restore it to the directory */
            if (res == FR_OK) {
              res = sync_fs(fs);
              fp->flag &= (BYTE)~FA_MODIFIED;
            }
          }
          FREE_NAMBUF();
        }
      } else
#endif
      {
        res = move_window(fs, fp->dir_sect);
        if (res == FR_OK) {
          dir = fp->dir_ptr;
          dir[DIR_Attr] |=
              AM_ARC; /* Set archive attribute to indicate that the file has been changed */
          st_clust(fp->obj.fs, dir, fp->obj.sclust); /* Update file allocation information  */
          st_dword(dir + DIR_FileSize, (DWORD)fp->obj.objsize); /* Update file size */
          st_dword(dir + DIR_ModTime, tm);                      /* Update modified time */
          st_word(dir + DIR_LstAccDate, 0);
          fs->wflag = 1;
          res = sync_fs(fs); /* Restore it to the directory */
          fp->flag &= (BYTE)~FA_MODIFIED;
        }
      }
    }
  }

  LEAVE_FF(fs, res);
}

#endif /* !FF_FS_READONLY */

/*-----------------------------------------------------------------------*/
/* Close File                                                            */
/*-----------------------------------------------------------------------*/

FRESULT f_close(FIL* fp /* Pointer to the file object to be closed */
) {
  FRESULT res;
  FATFS* fs;

#if !FF_FS_READONLY
  res = f_sync(fp); /* Flush cached data */
  if (res == FR_OK)
#endif
  {
    res = validate(&fp->obj, &fs); /* Lock volume */
    if (res == FR_OK) {
#if FF_FS_LOCK != 0
      res = dec_lock(fp->obj.lockid);   /* Decrement file open counter */
      if (res == FR_OK) fp->obj.fs = 0; /* Invalidate file object */
#else
      fp->obj.fs = 0;                                  /* Invalidate file object */
#endif
#if FF_FS_REENTRANT
      unlock_fs(fs, FR_OK); /* Unlock volume */
#endif
    }
  }
  return res;
}

#if FF_FS_RPATH >= 1
/*-----------------------------------------------------------------------*/
/* Change Current Directory or Current Drive, Get Current Directory      */
/*-----------------------------------------------------------------------*/

#if FF_VOLUMES >= 2
FRESULT f_chdrive(const TCHAR* path /* Drive number */
) {
  int vol;

  /* Get logical drive number */
  vol = get_ldnumber(&path);
  if (vol < 0) return FR_INVALID_DRIVE;

  CurrVol = (BYTE)vol; /* Set it as current volume */

  return FR_OK;
}
#endif

FRESULT f_chdir(const TCHAR* path /* Pointer to the directory path */
) {
  FRESULT res;
  FF_DIR dj;
  FATFS* fs;
  DEF_NAMBUF

  /* Get logical drive */
  res = find_volume(&path, &fs, 0);
  if (res == FR_OK) {
    dj.obj.fs = fs;
    INIT_NAMBUF(fs);
    res = follow_path(&dj, path); /* Follow the path */
    if (res == FR_OK) {           /* Follow completed */
      if (dj.fn[NSFLAG] & NS_NONAME) {
        fs->cdir = dj.obj.sclust; /* It is the start directory itself */
#if FF_FS_EXFAT
        if (fs->fs_type == FS_EXFAT) {
          fs->cdc_scl = dj.obj.c_scl;
          fs->cdc_size = dj.obj.c_size;
          fs->cdc_ofs = dj.obj.c_ofs;
        }
#endif
      } else {
        if (dj.obj.attr & AM_DIR) { /* It is a sub-directory */
#if FF_FS_EXFAT
          if (fs->fs_type == FS_EXFAT) {
            fs->cdir = ld_dword(fs->dirbuf + XDIR_FstClus); /* Sub-directory cluster */
            fs->cdc_scl = dj.obj.sclust; /* Save containing directory information */
            fs->cdc_size = ((DWORD)dj.obj.objsize & 0xFFFFFF00) | dj.obj.stat;
            fs->cdc_ofs = dj.blk_ofs;
          } else
#endif
          {
            fs->cdir = ld_clust(fs, dj.dir); /* Sub-directory cluster */
          }
        } else {
          res = FR_NO_PATH; /* Reached but a file */
        }
      }
    }
    FREE_NAMBUF();
    if (res == FR_NO_FILE) res = FR_NO_PATH;
  }

  LEAVE_FF(fs, res);
}

#if FF_FS_RPATH >= 2
FRESULT f_getcwd(TCHAR* buff, /* Pointer to the directory path */
                 UINT len     /* Size of path */
) {
  FRESULT res;
  FF_DIR dj;
  FATFS* fs;
  UINT i, n;
  DWORD ccl;
  TCHAR* tp;
  FILINFO fno;
  DEF_NAMBUF

  *buff = 0;
  /* Get logical drive */
  res = find_volume((const TCHAR**)&buff, &fs, 0); /* Get current volume */
  if (res == FR_OK) {
    dj.obj.fs = fs;
    INIT_NAMBUF(fs);
    i = len; /* Bottom of buffer (directory stack base) */
    if (!FF_FS_EXFAT ||
        fs->fs_type != FS_EXFAT) { /* (Cannot do getcwd on exFAT and returns root path) */
      dj.obj.sclust = fs->cdir;    /* Start to follow upper directory from current directory */
      while ((ccl = dj.obj.sclust) != 0) { /* Repeat while current directory is a sub-directory */
        res = dir_sdi(&dj, 1 * SZDIRE);    /* Get parent directory */
        if (res != FR_OK) break;
        res = move_window(fs, dj.sect);
        if (res != FR_OK) break;
        dj.obj.sclust = ld_clust(fs, dj.dir); /* Goto parent directory */
        res = dir_sdi(&dj, 0);
        if (res != FR_OK) break;
        do { /* Find the entry links to the child directory */
          res = dir_read(&dj, 0);
          if (res != FR_OK) break;
          if (ccl == ld_clust(fs, dj.dir)) break; /* Found the entry */
          res = dir_next(&dj, 0);
        } while (res == FR_OK);
        if (res == FR_NO_FILE) res = FR_INT_ERR; /* It cannot be 'not found'. */
        if (res != FR_OK) break;
        get_fileinfo(&dj, &fno); /* Get the directory name and push it to the buffer */
        for (n = 0; fno.fname[n]; n++)
          ;
        if (i < n + 3) {
          res = FR_NOT_ENOUGH_CORE;
          break;
        }
        while (n) buff[--i] = fno.fname[--n];
        buff[--i] = '/';
      }
    }
    tp = buff;
    if (res == FR_OK) {
#if FF_VOLUMES >= 2
      *tp++ = '0' + CurrVol; /* Put drive number */
      *tp++ = ':';
#endif
      if (i == len) { /* Root-directory */
        *tp++ = '/';
      } else { /* Sub-directroy */
        do     /* Add stacked path str */
          *tp++ = buff[i++];
        while (i < len);
      }
    }
    *tp = 0;
    FREE_NAMBUF();
  }

  LEAVE_FF(fs, res);
}

#endif /* FF_FS_RPATH >= 2 */
#endif /* FF_FS_RPATH >= 1 */

#if FF_FS_MINIMIZE <= 2
/*-----------------------------------------------------------------------*/
/* Seek File Read/Write Pointer                                          */
/*-----------------------------------------------------------------------*/

FRESULT f_lseek(FIL* fp,    /* Pointer to the file object */
                FSIZE_t ofs /* File pointer from top of file */
) {
  FRESULT res;
  FATFS* fs;
  DWORD clst, bcs, nsect;
  FSIZE_t ifptr;
#if FF_USE_FASTSEEK
  DWORD cl, pcl, ncl, tcl, dsc, tlen, ulen, *tbl;
#endif

  res = validate(&fp->obj, &fs); /* Check validity of the file object */
  if (res == FR_OK) res = (FRESULT)fp->err;
#if FF_FS_EXFAT && !FF_FS_READONLY
  if (res == FR_OK && fs->fs_type == FS_EXFAT) {
    res = fill_last_frag(&fp->obj, fp->clust,
                         0xFFFFFFFF); /* Fill last fragment on the FAT if needed */
  }
#endif
  if (res != FR_OK) LEAVE_FF(fs, res);

#if FF_USE_FASTSEEK
  if (fp->cltbl) {               /* Fast seek */
    if (ofs == CREATE_LINKMAP) { /* Create CLMT */
      tbl = fp->cltbl;
      tlen = *tbl++;
      ulen = 2;            /* Given table size and required table size */
      cl = fp->obj.sclust; /* Origin of the chain */
      if (cl != 0) {
        do {
          /* Get a fragment */
          tcl = cl;
          ncl = 0;
          ulen += 2; /* Top, length and used items */
          do {
            pcl = cl;
            ncl++;
            cl = get_fat(&fp->obj, cl);
            if (cl <= 1) ABORT(fs, FR_INT_ERR);
            if (cl == 0xFFFFFFFF) ABORT(fs, FR_DISK_ERR);
          } while (cl == pcl + 1);
          if (ulen <= tlen) { /* Store the length and top of the fragment */
            *tbl++ = ncl;
            *tbl++ = tcl;
          }
        } while (cl < fs->n_fatent); /* Repeat until end of chain */
      }
      *fp->cltbl = ulen; /* Number of items used */
      if (ulen <= tlen) {
        *tbl = 0; /* Terminate table */
      } else {
        res = FR_NOT_ENOUGH_CORE; /* Given table size is smaller than required */
      }
    } else {                                            /* Fast seek */
      if (ofs > fp->obj.objsize) ofs = fp->obj.objsize; /* Clip offset at the file size */
      fp->fptr = ofs;                                   /* Set file pointer */
      if (ofs > 0) {
        fp->clust = clmt_clust(fp, ofs - 1);
        dsc = clst2sect(fs, fp->clust);
        if (dsc == 0) ABORT(fs, FR_INT_ERR);
        dsc += (DWORD)((ofs - 1) / SS(fs)) & (fs->csize - 1);
        if (fp->fptr % SS(fs) && dsc != fp->sect) { /* Refill sector cache if needed */
#if !FF_FS_TINY
#if !FF_FS_READONLY
          if (fp->flag & FA_DIRTY) { /* Write-back dirty sector cache */
            if (disk_write(fs->pdrv, fp->buf, fp->sect, 1) != RES_OK) ABORT(fs, FR_DISK_ERR);
            fp->flag &= (BYTE)~FA_DIRTY;
          }
#endif
          if (disk_read(fs->pdrv, fp->buf, dsc, 1) != RES_OK)
            ABORT(fs, FR_DISK_ERR); /* Load current sector */
#endif
          fp->sect = dsc;
        }
      }
    }
  } else
#endif

  /* Normal Seek */
  {
#if FF_FS_EXFAT
    if (fs->fs_type != FS_EXFAT && ofs >= 0x100000000)
      ofs = 0xFFFFFFFF; /* Clip at 4 GiB - 1 if at FATxx */
#endif
    if (ofs > fp->obj.objsize &&
        (FF_FS_READONLY ||
         !(fp->flag & FA_WRITE))) { /* In read-only mode, clip offset with the file size */
      ofs = fp->obj.objsize;
    }
    ifptr = fp->fptr;
    fp->fptr = nsect = 0;
    if (ofs > 0) {
      bcs = (DWORD)fs->csize * SS(fs); /* Cluster size (byte) */
      if (ifptr > 0 &&
          (ofs - 1) / bcs >= (ifptr - 1) / bcs) {     /* When seek to same or following cluster, */
        fp->fptr = (ifptr - 1) & ~(FSIZE_t)(bcs - 1); /* start from the current cluster */
        ofs -= fp->fptr;
        clst = fp->clust;
      } else {                 /* When seek to back cluster, */
        clst = fp->obj.sclust; /* start from the first cluster */
#if !FF_FS_READONLY
        if (clst == 0) { /* If no cluster chain, create a new chain */
          clst = create_chain(&fp->obj, 0);
          if (clst == 1) ABORT(fs, FR_INT_ERR);
          if (clst == 0xFFFFFFFF) ABORT(fs, FR_DISK_ERR);
          fp->obj.sclust = clst;
        }
#endif
        fp->clust = clst;
      }
      if (clst != 0) {
        while (ofs > bcs) { /* Cluster following loop */
          ofs -= bcs;
          fp->fptr += bcs;
#if !FF_FS_READONLY
          if (fp->flag & FA_WRITE) { /* Check if in write mode or not */
            if (FF_FS_EXFAT &&
                fp->fptr >
                    fp->obj
                        .objsize) { /* No FAT chain object needs correct objsize to generate FAT value */
              fp->obj.objsize = fp->fptr;
              fp->flag |= FA_MODIFIED;
            }
            clst = create_chain(&fp->obj, clst); /* Follow chain with forceed stretch */
            if (clst == 0) {                     /* Clip file size in case of disk full */
              ofs = 0;
              break;
            }
          } else
#endif
          {
            clst = get_fat(&fp->obj, clst); /* Follow cluster chain if not in write mode */
          }
          if (clst == 0xFFFFFFFF) ABORT(fs, FR_DISK_ERR);
          if (clst <= 1 || clst >= fs->n_fatent) ABORT(fs, FR_INT_ERR);
          fp->clust = clst;
        }
        fp->fptr += ofs;
        if (ofs % SS(fs)) {
          nsect = clst2sect(fs, clst); /* Current sector */
          if (nsect == 0) ABORT(fs, FR_INT_ERR);
          nsect += (DWORD)(ofs / SS(fs));
        }
      }
    }
    if (!FF_FS_READONLY &&
        fp->fptr > fp->obj.objsize) { /* Set file change flag if the file size is extended */
      fp->obj.objsize = fp->fptr;
      fp->flag |= FA_MODIFIED;
    }
    if (fp->fptr % SS(fs) && nsect != fp->sect) { /* Fill sector cache if needed */
#if !FF_FS_TINY
#if !FF_FS_READONLY
      if (fp->flag & FA_DIRTY) { /* Write-back dirty sector cache */
        if (disk_write(fs->pdrv, fp->buf, fp->sect, 1) != RES_OK) ABORT(fs, FR_DISK_ERR);
        fp->flag &= (BYTE)~FA_DIRTY;
      }
#endif
      if (disk_read(fs->pdrv, fp->buf, nsect, 1) != RES_OK)
        ABORT(fs, FR_DISK_ERR); /* Fill sector cache */
#endif
      fp->sect = nsect;
    }
  }

  LEAVE_FF(fs, res);
}

#if FF_FS_MINIMIZE <= 1
/*-----------------------------------------------------------------------*/
/* Create a Directory Object                                             */
/*-----------------------------------------------------------------------*/

FRESULT f_opendir(FF_DIR* dp,       /* Pointer to directory object to create */
                  const TCHAR* path /* Pointer to the directory path */
) {
  FRESULT res;
  FATFS* fs;
  DEF_NAMBUF

  if (!dp) return FR_INVALID_OBJECT;

  /* Get logical drive */
  res = find_volume(&path, &fs, 0);
  if (res == FR_OK) {
    dp->obj.fs = fs;
    INIT_NAMBUF(fs);
    res = follow_path(dp, path);           /* Follow the path to the directory */
    if (res == FR_OK) {                    /* Follow completed */
      if (!(dp->fn[NSFLAG] & NS_NONAME)) { /* It is not the origin directory itself */
        if (dp->obj.attr & AM_DIR) {       /* This object is a sub-directory */
#if FF_FS_EXFAT
          if (fs->fs_type == FS_EXFAT) {
            dp->obj.c_scl = dp->obj.sclust; /* Get containing directory inforamation */
            dp->obj.c_size = ((DWORD)dp->obj.objsize & 0xFFFFFF00) | dp->obj.stat;
            dp->obj.c_ofs = dp->blk_ofs;
            dp->obj.sclust = ld_dword(fs->dirbuf + XDIR_FstClus); /* Get object allocation info */
            dp->obj.objsize = ld_qword(fs->dirbuf + XDIR_FileSize);
            dp->obj.stat = fs->dirbuf[XDIR_GenFlags] & 2;
          } else
#endif
          {
            dp->obj.sclust = ld_clust(fs, dp->dir); /* Get object allocation info */
          }
        } else { /* This object is a file */
          res = FR_NO_PATH;
        }
      }
      if (res == FR_OK) {
        dp->obj.id = fs->id;
        res = dir_sdi(dp, 0); /* Rewind directory */
#if FF_FS_LOCK != 0
        if (res == FR_OK) {
          if (dp->obj.sclust != 0) {
            dp->obj.lockid = inc_lock(dp, 0); /* Lock the sub directory */
            if (!dp->obj.lockid) res = FR_TOO_MANY_OPEN_FILES;
          } else {
            dp->obj.lockid = 0; /* Root directory need not to be locked */
          }
        }
#endif
      }
    }
    FREE_NAMBUF();
    if (res == FR_NO_FILE) res = FR_NO_PATH;
  }
  if (res != FR_OK) dp->obj.fs = 0; /* Invalidate the directory object if function faild */

  LEAVE_FF(fs, res);
}

/*-----------------------------------------------------------------------*/
/* Close Directory                                                       */
/*-----------------------------------------------------------------------*/

FRESULT f_closedir(FF_DIR* dp /* Pointer to the directory object to be closed */
) {
  FRESULT res;
  FATFS* fs;

  res = validate(&dp->obj, &fs); /* Check validity of the file object */
  if (res == FR_OK) {
#if FF_FS_LOCK != 0
    if (dp->obj.lockid) res = dec_lock(dp->obj.lockid); /* Decrement sub-directory open counter */
    if (res == FR_OK) dp->obj.fs = 0;                   /* Invalidate directory object */
#else
    dp->obj.fs = 0; /* Invalidate directory object */
#endif
#if FF_FS_REENTRANT
    unlock_fs(fs, FR_OK); /* Unlock volume */
#endif
  }
  return res;
}

/*-----------------------------------------------------------------------*/
/* Read Directory Entries in Sequence                                    */
/*-----------------------------------------------------------------------*/

FRESULT f_readdir(FF_DIR* dp,  /* Pointer to the open directory object */
                  FILINFO* fno /* Pointer to file information to return */
) {
  FRESULT res;
  FATFS* fs;
  DEF_NAMBUF

  res = validate(&dp->obj, &fs); /* Check validity of the directory object */
  if (res == FR_OK) {
    if (!fno) {
      res = dir_sdi(dp, 0); /* Rewind the directory object */
    } else {
      INIT_NAMBUF(fs);
      res = dir_read(dp, 0);                /* Read an item */
      if (res == FR_NO_FILE) res = FR_OK;   /* Ignore end of directory */
      if (res == FR_OK) {                   /* A valid entry is found */
        get_fileinfo(dp, fno);              /* Get the object information */
        res = dir_next(dp, 0);              /* Increment index for next */
        if (res == FR_NO_FILE) res = FR_OK; /* Ignore end of directory now */
      }
      FREE_NAMBUF();
    }
  }
  LEAVE_FF(fs, res);
}

#if FF_USE_FIND
/*-----------------------------------------------------------------------*/
/* Find Next File                                                        */
/*-----------------------------------------------------------------------*/

FRESULT f_findnext(FF_DIR* dp,  /* Pointer to the open directory object */
                   FILINFO* fno /* Pointer to the file information structure */
) {
  FRESULT res;

  for (;;) {
    res = f_readdir(dp, fno); /* Get a directory item */
    if (res != FR_OK || !fno || !fno->fname[0])
      break; /* Terminate if any error or end of directory */
    if (pattern_matching(dp->pat, fno->fname, 0, 0)) break; /* Test for the file name */
#if FF_USE_LFN && FF_USE_FIND == 2
    if (pattern_matching(dp->pat, fno->altname, 0, 0))
      break; /* Test for alternative name if exist */
#endif
  }
  return res;
}

/*-----------------------------------------------------------------------*/
/* Find First File                                                       */
/*-----------------------------------------------------------------------*/

FRESULT f_findfirst(FF_DIR* dp,          /* Pointer to the blank directory object */
                    FILINFO* fno,        /* Pointer to the file information structure */
                    const TCHAR* path,   /* Pointer to the directory to open */
                    const TCHAR* pattern /* Pointer to the matching pattern */
) {
  FRESULT res;

  dp->pat = pattern;         /* Save pointer to pattern string */
  res = f_opendir(dp, path); /* Open the target directory */
  if (res == FR_OK) {
    res = f_findnext(dp, fno); /* Find the first item */
  }
  return res;
}

#endif /* FF_USE_FIND */

#if FF_FS_MINIMIZE == 0
/*-----------------------------------------------------------------------*/
/* Get File Status                                                       */
/*-----------------------------------------------------------------------*/

FRESULT f_stat(const TCHAR* path, /* Pointer to the file path */
               FILINFO* fno       /* Pointer to file information to return */
) {
  FRESULT res;
  FF_DIR dj;
  DEF_NAMBUF

  /* Get logical drive */
  res = find_volume(&path, &dj.obj.fs, 0);
  if (res == FR_OK) {
    INIT_NAMBUF(dj.obj.fs);
    res = follow_path(&dj, path);      /* Follow the file path */
    if (res == FR_OK) {                /* Follow completed */
      if (dj.fn[NSFLAG] & NS_NONAME) { /* It is origin directory */
        res = FR_INVALID_NAME;
      } else { /* Found an object */
        if (fno) get_fileinfo(&dj, fno);
      }
    }
    FREE_NAMBUF();
  }

  LEAVE_FF(dj.obj.fs, res);
}

#if !FF_FS_READONLY
/*-----------------------------------------------------------------------*/
/* Get Number of Free Clusters                                           */
/*-----------------------------------------------------------------------*/

FRESULT f_getfree(const TCHAR* path, /* Path name of the logical drive number */
                  DWORD* nclst,      /* Pointer to a variable to return number of free clusters */
                  FATFS** fatfs /* Pointer to return pointer to corresponding filesystem object */
) {
  FRESULT res;
  FATFS* fs;
  DWORD nfree, clst, sect, stat;
  UINT i;
  FFOBJID obj;

  /* Get logical drive */
  res = find_volume(&path, &fs, 0);
  if (res == FR_OK) {
    *fatfs = fs; /* Return ptr to the fs object */
    /* If free_clst is valid, return it without full FAT scan */
    if (fs->free_clst <= fs->n_fatent - 2) {
      *nclst = fs->free_clst;
    } else {
      /* Scan FAT to obtain number of free clusters */
      nfree = 0;
      if (fs->fs_type == FS_FAT12) { /* FAT12: Scan bit field FAT entries */
        clst = 2;
        obj.fs = fs;
        do {
          stat = get_fat(&obj, clst);
          if (stat == 0xFFFFFFFF) {
            res = FR_DISK_ERR;
            break;
          }
          if (stat == 1) {
            res = FR_INT_ERR;
            break;
          }
          if (stat == 0) nfree++;
        } while (++clst < fs->n_fatent);
      } else {
#if FF_FS_EXFAT
        if (fs->fs_type == FS_EXFAT) { /* exFAT: Scan allocation bitmap */
          BYTE bm;
          UINT b;

          clst = fs->n_fatent - 2; /* Number of clusters */
          sect = fs->database;     /* Assuming bitmap starts at cluster 2 */
          i = 0;                   /* Offset in the sector */
          do {                     /* Counts numbuer of bits with zero in the bitmap */
            if (i == 0) {
              res = move_window(fs, sect++);
              if (res != FR_OK) break;
            }
            for (b = 8, bm = fs->win[i]; b && clst; b--, clst--) {
              if (!(bm & 1)) nfree++;
              bm >>= 1;
            }
            i = (i + 1) % SS(fs);
          } while (clst);
        } else
#endif
        {                      /* FAT16/32: Scan WORD/DWORD FAT entries */
          clst = fs->n_fatent; /* Number of entries */
          sect = fs->fatbase;  /* Top of the FAT */
          i = 0;               /* Offset in the sector */
          do {                 /* Counts numbuer of entries with zero in the FAT */
            if (i == 0) {
              res = move_window(fs, sect++);
              if (res != FR_OK) break;
            }
            if (fs->fs_type == FS_FAT16) {
              if (ld_word(fs->win + i) == 0) nfree++;
              i += 2;
            } else {
              if ((ld_dword(fs->win + i) & 0x0FFFFFFF) == 0) nfree++;
              i += 4;
            }
            i %= SS(fs);
          } while (--clst);
        }
      }
      *nclst = nfree;        /* Return the free clusters */
      fs->free_clst = nfree; /* Now free_clst is valid */
      fs->fsi_flag |= 1;     /* FAT32: FSInfo is to be updated */
    }
  }

  LEAVE_FF(fs, res);
}

/*-----------------------------------------------------------------------*/
/* Truncate File                                                         */
/*-----------------------------------------------------------------------*/

FRESULT f_truncate(FIL* fp /* Pointer to the file object */
) {
  FRESULT res;
  FATFS* fs;
  DWORD ncl;

  res = validate(&fp->obj, &fs); /* Check validity of the file object */
  if (res != FR_OK || (res = (FRESULT)fp->err) != FR_OK) LEAVE_FF(fs, res);
  if (!(fp->flag & FA_WRITE)) LEAVE_FF(fs, FR_DENIED); /* Check access mode */

  if (fp->fptr < fp->obj.objsize) { /* Process when fptr is not on the eof */
    if (fp->fptr == 0) {            /* When set file size to zero, remove entire cluster chain */
      res = remove_chain(&fp->obj, fp->obj.sclust, 0);
      fp->obj.sclust = 0;
    } else { /* When truncate a part of the file, remove remaining clusters */
      ncl = get_fat(&fp->obj, fp->clust);
      res = FR_OK;
      if (ncl == 0xFFFFFFFF) res = FR_DISK_ERR;
      if (ncl == 1) res = FR_INT_ERR;
      if (res == FR_OK && ncl < fs->n_fatent) {
        res = remove_chain(&fp->obj, ncl, fp->clust);
      }
    }
    fp->obj.objsize = fp->fptr; /* Set file size to current read/write point */
    fp->flag |= FA_MODIFIED;
#if !FF_FS_TINY
    if (res == FR_OK && (fp->flag & FA_DIRTY)) {
      if (disk_write(fs->pdrv, fp->buf, fp->sect, 1) != RES_OK) {
        res = FR_DISK_ERR;
      } else {
        fp->flag &= (BYTE)~FA_DIRTY;
      }
    }
#endif
    if (res != FR_OK) ABORT(fs, res);
  }

  LEAVE_FF(fs, res);
}

/*-----------------------------------------------------------------------*/
/* Delete a File/Directory                                               */
/*-----------------------------------------------------------------------*/

FRESULT f_unlink(const TCHAR* path /* Pointer to the file or directory path */
) {
  FRESULT res;
  FF_DIR dj, sdj;
  DWORD dclst = 0;
  FATFS* fs;
#if FF_FS_EXFAT
  FFOBJID obj;
#endif
  DEF_NAMBUF

  /* Get logical drive */
  res = find_volume(&path, &fs, FA_WRITE);
  if (res == FR_OK) {
    dj.obj.fs = fs;
    INIT_NAMBUF(fs);
    res = follow_path(&dj, path); /* Follow the file path */
    if (FF_FS_RPATH && res == FR_OK && (dj.fn[NSFLAG] & NS_DOT)) {
      res = FR_INVALID_NAME; /* Cannot remove dot entry */
    }
#if FF_FS_LOCK != 0
    if (res == FR_OK) res = chk_lock(&dj, 2); /* Check if it is an open object */
#endif
    if (res == FR_OK) { /* The object is accessible */
      if (dj.fn[NSFLAG] & NS_NONAME) {
        res = FR_INVALID_NAME; /* Cannot remove the origin directory */
      } else {
        if (dj.obj.attr & AM_RDO) {
          res = FR_DENIED; /* Cannot remove R/O object */
        }
      }
      if (res == FR_OK) {
#if FF_FS_EXFAT
        obj.fs = fs;
        if (fs->fs_type == FS_EXFAT) {
          obj.sclust = dclst = ld_dword(fs->dirbuf + XDIR_FstClus);
          obj.objsize = ld_qword(fs->dirbuf + XDIR_FileSize);
          obj.stat = fs->dirbuf[XDIR_GenFlags] & 2;
        } else
#endif
        {
          dclst = ld_clust(fs, dj.dir);
        }
        if (dj.obj.attr & AM_DIR) { /* Is it a sub-directory? */
#if FF_FS_RPATH != 0
          if (dclst == fs->cdir) { /* Is it the current directory? */
            res = FR_DENIED;
          } else
#endif
          {
            sdj.obj.fs = fs; /* Open the sub-directory */
            sdj.obj.sclust = dclst;
#if FF_FS_EXFAT
            if (fs->fs_type == FS_EXFAT) {
              sdj.obj.objsize = obj.objsize;
              sdj.obj.stat = obj.stat;
            }
#endif
            res = dir_sdi(&sdj, 0);
            if (res == FR_OK) {
              res = dir_read(&sdj, 0);            /* Read an item */
              if (res == FR_OK) res = FR_DENIED;  /* Not empty? */
              if (res == FR_NO_FILE) res = FR_OK; /* Empty? */
            }
          }
        }
      }
      if (res == FR_OK) {
        res = dir_remove(&dj);       /* Remove the directory entry */
        if (res == FR_OK && dclst) { /* Remove the cluster chain if exist */
#if FF_FS_EXFAT
          res = remove_chain(&obj, dclst, 0);
#else
          res = remove_chain(&dj.obj, dclst, 0);
#endif
        }
        if (res == FR_OK) res = sync_fs(fs);
      }
    }
    FREE_NAMBUF();
  }

  LEAVE_FF(fs, res);
}

/*-----------------------------------------------------------------------*/
/* Create a Directory                                                    */
/*-----------------------------------------------------------------------*/

FRESULT f_mkdir(const TCHAR* path /* Pointer to the directory path */
) {
  FRESULT res;
  FF_DIR dj;
  FATFS* fs;
  BYTE* dir;
  DWORD dcl, pcl, tm;
  DEF_NAMBUF

  /* Get logical drive */
  res = find_volume(&path, &fs, FA_WRITE);
  if (res == FR_OK) {
    dj.obj.fs = fs;
    INIT_NAMBUF(fs);
    res = follow_path(&dj, path);     /* Follow the file path */
    if (res == FR_OK) res = FR_EXIST; /* Any object with same name is already existing */
    if (FF_FS_RPATH && res == FR_NO_FILE && (dj.fn[NSFLAG] & NS_DOT)) {
      res = FR_INVALID_NAME;
    }
    if (res == FR_NO_FILE) {          /* Can create a new directory */
      dcl = create_chain(&dj.obj, 0); /* Allocate a cluster for the new directory table */
      dj.obj.objsize = (DWORD)fs->csize * SS(fs);
      res = FR_OK;
      if (dcl == 0) res = FR_DENIED; /* No space to allocate a new cluster */
      if (dcl == 1) res = FR_INT_ERR;
      if (dcl == 0xFFFFFFFF) res = FR_DISK_ERR;
      if (res == FR_OK) res = sync_window(fs); /* Flush FAT */
      tm = GET_FATTIME();
      if (res == FR_OK) {         /* Initialize the new directory table */
        res = dir_clear(fs, dcl); /* Clean up the new table */
        if (res == FR_OK &&
            (!FF_FS_EXFAT || fs->fs_type != FS_EXFAT)) { /* Create dot entries (FAT only) */
          dir = fs->win;
          mem_set(dir + DIR_Name, ' ', 11); /* Create "." entry */
          dir[DIR_Name] = '.';
          dir[DIR_Attr] = AM_DIR;
          st_dword(dir + DIR_ModTime, tm);
          st_clust(fs, dir, dcl);
          mem_cpy(dir + SZDIRE, dir, SZDIRE); /* Create ".." entry */
          dir[SZDIRE + 1] = '.';
          pcl = dj.obj.sclust;
          st_clust(fs, dir + SZDIRE, pcl);
          fs->wflag = 1;
        }
      }
      if (res == FR_OK) {
        res = dir_register(&dj); /* Register the object to the directoy */
      }
      if (res == FR_OK) {
#if FF_FS_EXFAT
        if (fs->fs_type == FS_EXFAT) {              /* Initialize directory entry block */
          st_dword(fs->dirbuf + XDIR_ModTime, tm);  /* Created time */
          st_dword(fs->dirbuf + XDIR_FstClus, dcl); /* Table start cluster */
          st_dword(fs->dirbuf + XDIR_FileSize,
                   (DWORD)dj.obj.objsize); /* File size needs to be valid */
          st_dword(fs->dirbuf + XDIR_ValidFileSize, (DWORD)dj.obj.objsize);
          fs->dirbuf[XDIR_GenFlags] = 3;  /* Initialize the object flag */
          fs->dirbuf[XDIR_Attr] = AM_DIR; /* Attribute */
          res = store_xdir(&dj);
        } else
#endif
        {
          dir = dj.dir;
          st_dword(dir + DIR_ModTime, tm); /* Created time */
          st_clust(fs, dir, dcl);          /* Table start cluster */
          dir[DIR_Attr] = AM_DIR;          /* Attribute */
          fs->wflag = 1;
        }
        if (res == FR_OK) {
          res = sync_fs(fs);
        }
      } else {
        remove_chain(&dj.obj, dcl, 0); /* Could not register, remove cluster chain */
      }
    }
    FREE_NAMBUF();
  }

  LEAVE_FF(fs, res);
}

/*-----------------------------------------------------------------------*/
/* Rename a File/Directory                                               */
/*-----------------------------------------------------------------------*/

FRESULT f_rename(const TCHAR* path_old, /* Pointer to the object name to be renamed */
                 const TCHAR* path_new  /* Pointer to the new name */
) {
  FRESULT res;
  FF_DIR djo, djn;
  FATFS* fs;
  BYTE buf[FF_FS_EXFAT ? SZDIRE * 2 : SZDIRE], *dir;
  DWORD dw;
  DEF_NAMBUF

  get_ldnumber(&path_new);                     /* Snip the drive number of new name off */
  res = find_volume(&path_old, &fs, FA_WRITE); /* Get logical drive of the old object */
  if (res == FR_OK) {
    djo.obj.fs = fs;
    INIT_NAMBUF(fs);
    res = follow_path(&djo, path_old); /* Check old object */
    if (res == FR_OK && (djo.fn[NSFLAG] & (NS_DOT | NS_NONAME)))
      res = FR_INVALID_NAME; /* Check validity of name */
#if FF_FS_LOCK != 0
    if (res == FR_OK) {
      res = chk_lock(&djo, 2);
    }
#endif
    if (res == FR_OK) { /* Object to be renamed is found */
#if FF_FS_EXFAT
      if (fs->fs_type == FS_EXFAT) { /* At exFAT volume */
        BYTE nf, nn;
        WORD nh;

        mem_cpy(buf, fs->dirbuf, SZDIRE * 2); /* Save 85+C0 entry of old object */
        mem_cpy(&djn, &djo, sizeof djo);
        res = follow_path(&djn, path_new); /* Make sure if new object name is not in use */
        if (res == FR_OK) {                /* Is new name already in use by any other object? */
          res = (djn.obj.sclust == djo.obj.sclust && djn.dptr == djo.dptr) ? FR_NO_FILE : FR_EXIST;
        }
        if (res == FR_NO_FILE) {    /* It is a valid path and no name collision */
          res = dir_register(&djn); /* Register the new entry */
          if (res == FR_OK) {
            nf = fs->dirbuf[XDIR_NumSec];
            nn = fs->dirbuf[XDIR_NumName];
            nh = ld_word(fs->dirbuf + XDIR_NameHash);
            mem_cpy(fs->dirbuf, buf, SZDIRE * 2); /* Restore 85+C0 entry */
            fs->dirbuf[XDIR_NumSec] = nf;
            fs->dirbuf[XDIR_NumName] = nn;
            st_word(fs->dirbuf + XDIR_NameHash, nh);
            if (!(fs->dirbuf[XDIR_Attr] & AM_DIR))
              fs->dirbuf[XDIR_Attr] |= AM_ARC; /* Set archive attribute if it is a file */
            /* Start of critical section where an interruption can cause a cross-link */
            res = store_xdir(&djn);
          }
        }
      } else
#endif
      {                                      /* At FAT/FAT32 volume */
        mem_cpy(buf, djo.dir, SZDIRE);       /* Save directory entry of the object */
        mem_cpy(&djn, &djo, sizeof(FF_DIR)); /* Duplicate the directory object */
        res = follow_path(&djn, path_new);   /* Make sure if new object name is not in use */
        if (res == FR_OK) {                  /* Is new name already in use by any other object? */
          res = (djn.obj.sclust == djo.obj.sclust && djn.dptr == djo.dptr) ? FR_NO_FILE : FR_EXIST;
        }
        if (res == FR_NO_FILE) {    /* It is a valid path and no name collision */
          res = dir_register(&djn); /* Register the new entry */
          if (res == FR_OK) {
            dir = djn.dir; /* Copy directory entry of the object except name */
            mem_cpy(dir + 13, buf + 13, SZDIRE - 13);
            dir[DIR_Attr] = buf[DIR_Attr];
            if (!(dir[DIR_Attr] & AM_DIR))
              dir[DIR_Attr] |= AM_ARC; /* Set archive attribute if it is a file */
            fs->wflag = 1;
            if ((dir[DIR_Attr] & AM_DIR) &&
                djo.obj.sclust !=
                    djn.obj.sclust) { /* Update .. entry in the sub-directory if needed */
              dw = clst2sect(fs, ld_clust(fs, dir));
              if (dw == 0) {
                res = FR_INT_ERR;
              } else {
                /* Start of critical section where an interruption can cause a cross-link */
                res = move_window(fs, dw);
                dir = fs->win + SZDIRE * 1; /* Ptr to .. entry */
                if (res == FR_OK && dir[1] == '.') {
                  st_clust(fs, dir, djn.obj.sclust);
                  fs->wflag = 1;
                }
              }
            }
          }
        }
      }
      if (res == FR_OK) {
        res = dir_remove(&djo); /* Remove old entry */
        if (res == FR_OK) {
          res = sync_fs(fs);
        }
      }
      /* End of the critical section */
    }
    FREE_NAMBUF();
  }

  LEAVE_FF(fs, res);
}

#endif /* !FF_FS_READONLY */
#endif /* FF_FS_MINIMIZE == 0 */
#endif /* FF_FS_MINIMIZE <= 1 */
#endif /* FF_FS_MINIMIZE <= 2 */

#if FF_USE_CHMOD && !FF_FS_READONLY
/*-----------------------------------------------------------------------*/
/* Change Attribute                                                      */
/*-----------------------------------------------------------------------*/

FRESULT f_chmod(const TCHAR* path, /* Pointer to the file path */
                BYTE attr,         /* Attribute bits */
                BYTE mask          /* Attribute mask to change */
) {
  FRESULT res;
  FF_DIR dj;
  FATFS* fs;
  DEF_NAMBUF

  res = find_volume(&path, &fs, FA_WRITE); /* Get logical drive */
  if (res == FR_OK) {
    dj.obj.fs = fs;
    INIT_NAMBUF(fs);
    res = follow_path(&dj, path); /* Follow the file path */
    if (res == FR_OK && (dj.fn[NSFLAG] & (NS_DOT | NS_NONAME)))
      res = FR_INVALID_NAME; /* Check object validity */
    if (res == FR_OK) {
      mask &= AM_RDO | AM_HID | AM_SYS | AM_ARC; /* Valid attribute mask */
#if FF_FS_EXFAT
      if (fs->fs_type == FS_EXFAT) {
        fs->dirbuf[XDIR_Attr] =
            (attr & mask) | (fs->dirbuf[XDIR_Attr] & (BYTE)~mask); /* Apply attribute change */
        res = store_xdir(&dj);
      } else
#endif
      {
        dj.dir[DIR_Attr] =
            (attr & mask) | (dj.dir[DIR_Attr] & (BYTE)~mask); /* Apply attribute change */
        fs->wflag = 1;
      }
      if (res == FR_OK) {
        res = sync_fs(fs);
      }
    }
    FREE_NAMBUF();
  }

  LEAVE_FF(fs, res);
}

/*-----------------------------------------------------------------------*/
/* Change Timestamp                                                      */
/*-----------------------------------------------------------------------*/

FRESULT f_utime(const TCHAR* path, /* Pointer to the file/directory name */
                const FILINFO* fno /* Pointer to the timestamp to be set */
) {
  FRESULT res;
  FF_DIR dj;
  FATFS* fs;
  DEF_NAMBUF

  res = find_volume(&path, &fs, FA_WRITE); /* Get logical drive */
  if (res == FR_OK) {
    dj.obj.fs = fs;
    INIT_NAMBUF(fs);
    res = follow_path(&dj, path); /* Follow the file path */
    if (res == FR_OK && (dj.fn[NSFLAG] & (NS_DOT | NS_NONAME)))
      res = FR_INVALID_NAME; /* Check object validity */
    if (res == FR_OK) {
#if FF_FS_EXFAT
      if (fs->fs_type == FS_EXFAT) {
        st_dword(fs->dirbuf + XDIR_ModTime, (DWORD)fno->fdate << 16 | fno->ftime);
        res = store_xdir(&dj);
      } else
#endif
      {
        st_dword(dj.dir + DIR_ModTime, (DWORD)fno->fdate << 16 | fno->ftime);
        fs->wflag = 1;
      }
      if (res == FR_OK) {
        res = sync_fs(fs);
      }
    }
    FREE_NAMBUF();
  }

  LEAVE_FF(fs, res);
}

#endif /* FF_USE_CHMOD && !FF_FS_READONLY */

#if FF_USE_LABEL
/*-----------------------------------------------------------------------*/
/* Get Volume Label                                                      */
/*-----------------------------------------------------------------------*/

FRESULT f_getlabel(const TCHAR* path, /* Path name of the logical drive number */
                   TCHAR* label,      /* Pointer to a buffer to store the volume label */
                   DWORD* vsn         /* Pointer to a variable to store the volume serial number */
) {
  FRESULT res;
  FF_DIR dj;
  FATFS* fs;
  UINT si, di;
#if (FF_LFN_UNICODE && FF_USE_LFN) || FF_FS_EXFAT
  WCHAR w;
#endif

  /* Get logical drive */
  res = find_volume(&path, &fs, 0);

  /* Get volume label */
  if (res == FR_OK && label) {
    dj.obj.fs = fs;
    dj.obj.sclust = 0; /* Open root directory */
    res = dir_sdi(&dj, 0);
    if (res == FR_OK) {
      res = dir_read(&dj, 1); /* Find a volume label entry */
      if (res == FR_OK) {
#if FF_FS_EXFAT
        if (fs->fs_type == FS_EXFAT) {
          for (si = di = 0; si < dj.dir[XDIR_NumLabel];
               si++) { /* Extract volume label from 83 entry */
            w = ld_word(dj.dir + XDIR_Label + si * 2);
#if !FF_LFN_UNICODE                      /* ANSI/OEM API */
            w = ff_uni2oem(w, CODEPAGE); /* Unicode -> OEM */
            if (w == 0) w = '?';         /* Replace wrong char with '?' */
            if (w >= 0x100) label[di++] = (char)(w >> 8);
#endif
            label[di++] = (TCHAR)w;
          }
          label[di] = 0;
        } else
#endif
        {
          si = di = 0; /* Extract volume label from AM_VOL entry with code comversion */
          do {
#if FF_LFN_UNICODE && FF_USE_LFN /* Unicode API */
            w = (si < 11) ? dj.dir[si++] : ' ';
            if (dbc_1st((BYTE)w) && si < 11 && dbc_2nd(dj.dir[si])) {
              w = w << 8 | dj.dir[si++];
            }
            label[di++] = ff_oem2uni(w, CODEPAGE); /* OEM -> Unicode */
#else                                              /* ANSI/OEM API */
            label[di++] = dj.dir[si++];
#endif
          } while (di < 11);
          do { /* Truncate trailing spaces */
            label[di] = 0;
            if (di == 0) break;
          } while (label[--di] == ' ');
        }
      }
    }
    if (res == FR_NO_FILE) { /* No label entry and return nul string */
      label[0] = 0;
      res = FR_OK;
    }
  }

  /* Get volume serial number */
  if (res == FR_OK && vsn) {
    res = move_window(fs, fs->volbase);
    if (res == FR_OK) {
      switch (fs->fs_type) {
        case FS_EXFAT:
          di = BPB_VolIDEx;
          break;

        case FS_FAT32:
          di = BS_VolID32;
          break;

        default:
          di = BS_VolID;
      }
      *vsn = ld_dword(fs->win + di);
    }
  }

  LEAVE_FF(fs, res);
}

#if !FF_FS_READONLY
/*-----------------------------------------------------------------------*/
/* Set Volume Label                                                      */
/*-----------------------------------------------------------------------*/

FRESULT f_setlabel(const TCHAR* label /* Pointer to the volume label to set */
) {
  FRESULT res;
  FF_DIR dj;
  FATFS* fs;
  BYTE dirvn[22];
  UINT i, j, slen;
  WCHAR w;
  static const char badchr[] = "\"*+,.:;<=>\?[]|\x7F";

  /* Get logical drive */
  res = find_volume(&label, &fs, FA_WRITE);
  if (res != FR_OK) LEAVE_FF(fs, res);
  dj.obj.fs = fs;

  /* Get length of given volume label */
  for (slen = 0; (UINT)label[slen] >= ' '; slen++)
    ; /* Get name length */

#if FF_FS_EXFAT
  if (fs->fs_type == FS_EXFAT) { /* On the exFAT volume */
    for (i = j = 0; i < slen;) { /* Create volume label in directory form */
      w = label[i++];
#if !FF_LFN_UNICODE /* ANSI/OEM API */
      if (dbc_1st((BYTE)w)) {
        w = (i < slen && dbc_2nd((BYTE)label[i])) ? w << 8 | (BYTE)label[i++] : 0;
      }
      w = ff_oem2uni(w, CODEPAGE);
#endif
      if (w == 0 || chk_chr(badchr, w) ||
          j == 22) { /* Check validity check validity of the volume label */
        LEAVE_FF(fs, FR_INVALID_NAME);
      }
      st_word(dirvn + j, w);
      j += 2;
    }
    slen = j;
  } else
#endif
  { /* On the FAT/FAT32 volume */
    for (; slen && label[slen - 1] == ' '; slen--)
      ;              /* Remove trailing spaces */
    if (slen != 0) { /* Is there a volume label to be set? */
      dirvn[0] = 0;
      i = j = 0; /* Create volume label in directory form */
      do {
#if FF_LFN_UNICODE && FF_USE_LFN /* Unicode API */
        w = ff_uni2oem(ff_wtoupper(label[i++]), CODEPAGE);
#else /* ANSI/OEM API */
        w = (BYTE)label[i++];
        if (dbc_1st((BYTE)w)) {
          w = (j < 10 && i < slen && dbc_2nd((BYTE)label[i])) ? w << 8 | (BYTE)label[i++] : 0;
        }
#if FF_USE_LFN
        w = ff_uni2oem(ff_wtoupper(ff_oem2uni(w, CODEPAGE)), CODEPAGE);
#else
        if (IsLower(w)) w -= 0x20;                   /* To upper ASCII characters */
#if FF_CODE_PAGE == 0
        if (ExCvt && w >= 0x80) w = ExCvt[w - 0x80]; /* To upper extended characters (SBCS cfg) */
#elif FF_CODE_PAGE < 900
        if (w >= 0x80) w = ExCvt[w - 0x80]; /* To upper extended characters (SBCS cfg) */
#endif
#endif
#endif
        if (w == 0 || chk_chr(badchr, w) ||
            j >= (UINT)((w >= 0x100) ? 10 : 11)) { /* Reject invalid characters for volume label */
          LEAVE_FF(fs, FR_INVALID_NAME);
        }
        if (w >= 0x100) dirvn[j++] = (BYTE)(w >> 8);
        dirvn[j++] = (BYTE)w;
      } while (i < slen);
      while (j < 11) dirvn[j++] = ' ';                     /* Fill remaining name field */
      if (dirvn[0] == DDEM) LEAVE_FF(fs, FR_INVALID_NAME); /* Reject illegal name (heading DDEM) */
    }
  }

  /* Set volume label */
  dj.obj.sclust = 0; /* Open root directory */
  res = dir_sdi(&dj, 0);
  if (res == FR_OK) {
    res = dir_read(&dj, 1); /* Get volume label entry */
    if (res == FR_OK) {
      if (FF_FS_EXFAT && fs->fs_type == FS_EXFAT) {
        dj.dir[XDIR_NumLabel] = (BYTE)(slen / 2); /* Change the volume label */
        mem_cpy(dj.dir + XDIR_Label, dirvn, slen);
      } else {
        if (slen != 0) {
          mem_cpy(dj.dir, dirvn, 11); /* Change the volume label */
        } else {
          dj.dir[DIR_Name] = DDEM; /* Remove the volume label */
        }
      }
      fs->wflag = 1;
      res = sync_fs(fs);
    } else { /* No volume label entry or an error */
      if (res == FR_NO_FILE) {
        res = FR_OK;
        if (slen != 0) {           /* Create a volume label entry */
          res = dir_alloc(&dj, 1); /* Allocate an entry */
          if (res == FR_OK) {
            mem_set(dj.dir, 0, SZDIRE); /* Clear the entry */
            if (FF_FS_EXFAT && fs->fs_type == FS_EXFAT) {
              dj.dir[XDIR_Type] = 0x83; /* Create 83 entry */
              dj.dir[XDIR_NumLabel] = (BYTE)(slen / 2);
              mem_cpy(dj.dir + XDIR_Label, dirvn, slen);
            } else {
              dj.dir[DIR_Attr] = AM_VOL; /* Create volume label entry */
              mem_cpy(dj.dir, dirvn, 11);
            }
            fs->wflag = 1;
            res = sync_fs(fs);
          }
        }
      }
    }
  }

  LEAVE_FF(fs, res);
}

#endif /* !FF_FS_READONLY */
#endif /* FF_USE_LABEL */

#if FF_USE_EXPAND && !FF_FS_READONLY
/*-----------------------------------------------------------------------*/
/* Allocate a Contiguous Blocks to the File                              */
/*-----------------------------------------------------------------------*/

FRESULT f_expand(FIL* fp,     /* Pointer to the file object */
                 FSIZE_t fsz, /* File size to be expanded to */
                 BYTE opt     /* Operation mode 0:Find and prepare or 1:Find and allocate */
) {
  FRESULT res;
  FATFS* fs;
  DWORD n, clst, stcl, scl, ncl, tcl, lclst;

  res = validate(&fp->obj, &fs); /* Check validity of the file object */
  if (res != FR_OK || (res = (FRESULT)fp->err) != FR_OK) LEAVE_FF(fs, res);
  if (fsz == 0 || fp->obj.objsize != 0 || !(fp->flag & FA_WRITE)) LEAVE_FF(fs, FR_DENIED);
#if FF_FS_EXFAT
  if (fs->fs_type != FS_EXFAT && fsz >= 0x100000000)
    LEAVE_FF(fs, FR_DENIED); /* Check if in size limit */
#endif
  n = (DWORD)fs->csize * SS(fs);                      /* Cluster size */
  tcl = (DWORD)(fsz / n) + ((fsz & (n - 1)) ? 1 : 0); /* Number of clusters required */
  stcl = fs->last_clst;
  lclst = 0;
  if (stcl < 2 || stcl >= fs->n_fatent) stcl = 2;

#if FF_FS_EXFAT
  if (fs->fs_type == FS_EXFAT) {
    scl = find_bitmap(fs, stcl, tcl); /* Find a contiguous cluster block */
    if (scl == 0) res = FR_DENIED;    /* No contiguous cluster block was found */
    if (scl == 0xFFFFFFFF) res = FR_DISK_ERR;
    if (res == FR_OK) {                       /* A contiguous free area is found */
      if (opt) {                              /* Allocate it now */
        res = change_bitmap(fs, scl, tcl, 1); /* Mark the cluster block 'in use' */
        lclst = scl + tcl - 1;
      } else { /* Set it as suggested point for next allocation */
        lclst = scl - 1;
      }
    }
  } else
#endif
  {
    scl = clst = stcl;
    ncl = 0;
    for (;;) { /* Find a contiguous cluster block */
      n = get_fat(&fp->obj, clst);
      if (++clst >= fs->n_fatent) clst = 2;
      if (n == 1) {
        res = FR_INT_ERR;
        break;
      }
      if (n == 0xFFFFFFFF) {
        res = FR_DISK_ERR;
        break;
      }
      if (n == 0) {              /* Is it a free cluster? */
        if (++ncl == tcl) break; /* Break if a contiguous cluster block is found */
      } else {
        scl = clst;
        ncl = 0; /* Not a free cluster */
      }
      if (clst == stcl) {
        res = FR_DENIED;
        break;
      } /* No contiguous cluster? */
    }
    if (res == FR_OK) {                             /* A contiguous free area is found */
      if (opt) {                                    /* Allocate it now */
        for (clst = scl, n = tcl; n; clst++, n--) { /* Create a cluster chain on the FAT */
          res = put_fat(fs, clst, (n == 1) ? 0xFFFFFFFF : clst + 1);
          if (res != FR_OK) break;
          lclst = clst;
        }
      } else { /* Set it as suggested point for next allocation */
        lclst = scl - 1;
      }
    }
  }

  if (res == FR_OK) {
    fs->last_clst = lclst;  /* Set suggested start cluster to start next */
    if (opt) {              /* Is it allocated now? */
      fp->obj.sclust = scl; /* Update object allocation information */
      fp->obj.objsize = fsz;
      if (FF_FS_EXFAT) fp->obj.stat = 2; /* Set status 'contiguous chain' */
      fp->flag |= FA_MODIFIED;
      if (fs->free_clst <= fs->n_fatent - 2) { /* Update FSINFO */
        fs->free_clst -= tcl;
        fs->fsi_flag |= 1;
      }
    }
  }

  LEAVE_FF(fs, res);
}

#endif /* FF_USE_EXPAND && !FF_FS_READONLY */

#if FF_USE_FORWARD
/*-----------------------------------------------------------------------*/
/* Forward Data to the Stream Directly                                   */
/*-----------------------------------------------------------------------*/

FRESULT f_forward(FIL* fp,                         /* Pointer to the file object */
                  UINT (*func)(const BYTE*, UINT), /* Pointer to the streaming function */
                  UINT btf,                        /* Number of bytes to forward */
                  UINT* bf                         /* Pointer to number of bytes forwarded */
) {
  FRESULT res;
  FATFS* fs;
  DWORD clst, sect;
  FSIZE_t remain;
  UINT rcnt, csect;
  BYTE* dbuf;

  *bf = 0;                       /* Clear transfer byte counter */
  res = validate(&fp->obj, &fs); /* Check validity of the file object */
  if (res != FR_OK || (res = (FRESULT)fp->err) != FR_OK) LEAVE_FF(fs, res);
  if (!(fp->flag & FA_READ)) LEAVE_FF(fs, FR_DENIED); /* Check access mode */

  remain = fp->obj.objsize - fp->fptr;
  if (btf > remain) btf = (UINT)remain; /* Truncate btf by remaining bytes */

  for (; btf && (*func)(0, 0); /* Repeat until all data transferred or stream goes busy */
       fp->fptr += rcnt, *bf += rcnt, btf -= rcnt) {
    csect = (UINT)(fp->fptr / SS(fs) & (fs->csize - 1)); /* Sector offset in the cluster */
    if (fp->fptr % SS(fs) == 0) {                        /* On the sector boundary? */
      if (csect == 0) {                                  /* On the cluster boundary? */
        clst = (fp->fptr == 0) ?                         /* On the top of the file? */
                   fp->obj.sclust
                               : get_fat(&fp->obj, fp->clust);
        if (clst <= 1) ABORT(fs, FR_INT_ERR);
        if (clst == 0xFFFFFFFF) ABORT(fs, FR_DISK_ERR);
        fp->clust = clst; /* Update current cluster */
      }
    }
    sect = clst2sect(fs, fp->clust); /* Get current data sector */
    if (sect == 0) ABORT(fs, FR_INT_ERR);
    sect += csect;
#if FF_FS_TINY
    if (move_window(fs, sect) != FR_OK)
      ABORT(fs, FR_DISK_ERR); /* Move sector window to the file data */
    dbuf = fs->win;
#else
    if (fp->sect != sect) {      /* Fill sector cache with file data */
#if !FF_FS_READONLY
      if (fp->flag & FA_DIRTY) { /* Write-back dirty sector cache */
        if (disk_write(fs->pdrv, fp->buf, fp->sect, 1) != RES_OK) ABORT(fs, FR_DISK_ERR);
        fp->flag &= (BYTE)~FA_DIRTY;
      }
#endif
      if (disk_read(fs->pdrv, fp->buf, sect, 1) != RES_OK) ABORT(fs, FR_DISK_ERR);
    }
    dbuf = fp->buf;
#endif
    fp->sect = sect;
    rcnt = SS(fs) - (UINT)fp->fptr % SS(fs);                /* Number of bytes left in the sector */
    if (rcnt > btf) rcnt = btf;                             /* Clip it by btr if needed */
    rcnt = (*func)(dbuf + ((UINT)fp->fptr % SS(fs)), rcnt); /* Forward the file data */
    if (rcnt == 0) ABORT(fs, FR_INT_ERR);
  }

  LEAVE_FF(fs, FR_OK);
}
#endif /* FF_USE_FORWARD */

#if FF_USE_MKFS && !FF_FS_READONLY
/*-----------------------------------------------------------------------*/
/* Create an FAT/exFAT volume                                            */
/*-----------------------------------------------------------------------*/

FRESULT f_mkfs(const TCHAR* path, /* Logical drive number */
               BYTE opt,          /* Format option */
               DWORD au,          /* Size of allocation unit (cluster) [byte] */
               void* work,        /* Pointer to working buffer */
               UINT len           /* Size of working buffer */
) {
  const UINT n_fats = 1;      /* Number of FATs for FAT/FAT32 volume (1 or 2) */
  const UINT n_rootdir = 512; /* Number of root directory entries for FAT volume */
  static const WORD cst[] = {1,   4,   16, 64,
                             256, 512, 0}; /* Cluster size boundary for FAT volume (4Ks unit) */
  static const WORD cst32[] = {1,  2,  4, 8,
                               16, 32, 0}; /* Cluster size boundary for FAT32 volume (128Ks unit) */
  BYTE fmt, sys, *buf, *pte, pdrv, part;
  WORD ss;
  DWORD szb_buf, sz_buf, sz_blk, n_clst, pau, sect, nsect, n;
  DWORD b_vol, b_fat, b_data;           /* Base LBA for volume, fat, data */
  DWORD sz_vol, sz_rsv, sz_fat, sz_dir; /* Size for volume, fat, dir, data */
  UINT i;
  int vol;
  DSTATUS stat;
#if FF_USE_TRIM || FF_FS_EXFAT
  DWORD tbl[3];
#endif

  /* Check mounted drive and clear work area */
  vol = get_ldnumber(&path); /* Get target logical drive */
  if (vol < 0) return FR_INVALID_DRIVE;
  if (FatFs[vol]) FatFs[vol]->fs_type = 0; /* Clear the volume */
  pdrv = LD2PD(vol);                       /* Physical drive */
  part = LD2PT(vol); /* Partition (0:create as new, 1-4:get from partition table) */

  /* Check physical drive status */
  stat = disk_initialize(pdrv);
  if (stat & STA_NOINIT) return FR_NOT_READY;
  if (stat & STA_PROTECT) return FR_WRITE_PROTECTED;
  if (disk_ioctl(pdrv, GET_BLOCK_SIZE, &sz_blk) != RES_OK || !sz_blk || sz_blk > 32768 ||
      (sz_blk & (sz_blk - 1)))
    sz_blk = 1;            /* Erase block to align data area */
#if FF_MAX_SS != FF_MIN_SS /* Get sector size of the medium if variable sector size cfg. */
  if (disk_ioctl(pdrv, GET_SECTOR_SIZE, &ss) != RES_OK) return FR_DISK_ERR;
  if (ss > FF_MAX_SS || ss < FF_MIN_SS || (ss & (ss - 1))) return FR_DISK_ERR;
#else
  ss = FF_MAX_SS;
#endif
  if ((au != 0 && au < ss) || au > 0x1000000 || (au & (au - 1)))
    return FR_INVALID_PARAMETER; /* Check if au is valid */
  au /= ss;                      /* Cluster size in unit of sector */

  /* Get working buffer */
  buf = (BYTE*)work;     /* Working buffer */
  sz_buf = len / ss;     /* Size of working buffer (sector) */
  szb_buf = sz_buf * ss; /* Size of working buffer (byte) */
  if (szb_buf == 0) return FR_MKFS_ABORTED;

  /* Determine where the volume to be located (b_vol, sz_vol) */
  if (FF_MULTI_PARTITION && part != 0) {
    /* Get partition information from partition table in the MBR */
    if (disk_read(pdrv, buf, 0, 1) != RES_OK) return FR_DISK_ERR; /* Load MBR */
    if (ld_word(buf + BS_55AA) != 0xAA55) return FR_MKFS_ABORTED; /* Check if MBR is valid */
    pte = buf + (MBR_Table + (part - 1) * SZ_PTE);
    if (!pte[PTE_System]) return FR_MKFS_ABORTED; /* No partition? */
    b_vol = ld_dword(pte + PTE_StLba);            /* Get volume start sector */
    sz_vol = ld_dword(pte + PTE_SizLba);          /* Get volume size */
  } else {
    /* Create a single-partition in this function */
    if (disk_ioctl(pdrv, GET_SECTOR_COUNT, &sz_vol) != RES_OK) return FR_DISK_ERR;
    b_vol = (opt & FM_SFD) ? 0 : 63; /* Volume start sector */
    if (sz_vol < b_vol) return FR_MKFS_ABORTED;
    sz_vol -= b_vol; /* Volume size */
  }
  if (sz_vol < 128) return FR_MKFS_ABORTED; /* Check if volume size is >=128s */

  /* Pre-determine the FAT type */
  do {
    if (FF_FS_EXFAT && (opt & FM_EXFAT)) { /* exFAT possible? */
      if ((opt & FM_ANY) == FM_EXFAT || sz_vol >= 0x4000000 ||
          au > 128) { /* exFAT only, vol >= 64Ms or au > 128s ? */
        fmt = FS_EXFAT;
        break;
      }
    }
    if (au > 128) return FR_INVALID_PARAMETER;             /* Too large au for FAT/FAT32 */
    if (opt & FM_FAT32) {                                  /* FAT32 possible? */
      if ((opt & FM_ANY) == FM_FAT32 || !(opt & FM_FAT)) { /* FAT32 only or no-FAT? */
        fmt = FS_FAT32;
        break;
      }
    }
    if (!(opt & FM_FAT)) return FR_INVALID_PARAMETER; /* no-FAT? */
    fmt = FS_FAT16;
  } while (0);

#if FF_FS_EXFAT
  if (fmt == FS_EXFAT) { /* Create an exFAT volume */
    DWORD szb_bit, szb_case, sum, nb, cl;
    WCHAR ch, si;
    UINT j, st;
    BYTE b;

    if (sz_vol < 0x1000) return FR_MKFS_ABORTED; /* Too small volume? */
#if FF_USE_TRIM
    tbl[0] = b_vol;
    tbl[1] = b_vol + sz_vol - 1; /* Inform the device the volume area may be erased */
    disk_ioctl(pdrv, CTRL_TRIM, tbl);
#endif
    /* Determine FAT location, data location and number of clusters */
    if (au == 0) { /* au auto-selection */
      au = 8;
      if (sz_vol >= 0x80000) au = 64;    /* >= 512Ks */
      if (sz_vol >= 0x4000000) au = 256; /* >= 64Ms */
    }
    b_fat = b_vol + 32;                             /* FAT start at offset 32 */
    sz_fat = ((sz_vol / au + 2) * 4 + ss - 1) / ss; /* Number of FAT sectors */
    b_data = (b_fat + sz_fat + sz_blk - 1) &
             ~(sz_blk - 1); /* Align data area to the erase block boundary */
    if (b_data >= sz_vol / 2) return FR_MKFS_ABORTED; /* Too small volume? */
    n_clst = (sz_vol - (b_data - b_vol)) / au;        /* Number of clusters */
    if (n_clst < 16) return FR_MKFS_ABORTED;          /* Too few clusters? */
    if (n_clst > MAX_EXFAT) return FR_MKFS_ABORTED;   /* Too many clusters? */

    szb_bit = (n_clst + 7) / 8;                   /* Size of allocation bitmap */
    tbl[0] = (szb_bit + au * ss - 1) / (au * ss); /* Number of allocation bitmap clusters */

    /* Create a compressed up-case table */
    sect = b_data + au * tbl[0]; /* Table start sector */
    sum = 0;                     /* Table checksum to be stored in the 82 entry */
    st = si = i = j = szb_case = 0;
    do {
      switch (st) {
        case 0:
          ch = ff_wtoupper(si); /* Get an up-case char */
          if (ch != si) {
            si++;
            break; /* Store the up-case char if exist */
          }
          for (j = 1; (WCHAR)(si + j) && (WCHAR)(si + j) == ff_wtoupper((WCHAR)(si + j)); j++)
            ; /* Get run length of no-case block */
          if (j >= 128) {
            ch = 0xFFFF;
            st = 2;
            break; /* Compress the no-case block if run is >= 128 */
          }
          st = 1; /* Do not compress short run */
                  /* go to next case */
        case 1:
          ch = si++; /* Fill the short run */
          if (--j == 0) st = 0;
          break;

        default:
          ch = (WCHAR)j;
          si += j; /* Number of chars to skip */
          st = 0;
      }
      sum = xsum32(buf[i + 0] = (BYTE)ch, sum); /* Put it into the write buffer */
      sum = xsum32(buf[i + 1] = (BYTE)(ch >> 8), sum);
      i += 2;
      szb_case += 2;
      if (si == 0 || i == szb_buf) { /* Write buffered data when buffer full or end of process */
        n = (i + ss - 1) / ss;
        if (disk_write(pdrv, buf, sect, n) != RES_OK) return FR_DISK_ERR;
        sect += n;
        i = 0;
      }
    } while (si);
    tbl[1] = (szb_case + au * ss - 1) / (au * ss); /* Number of up-case table clusters */
    tbl[2] = 1;                                    /* Number of root dir clusters */

    /* Initialize the allocation bitmap */
    sect = b_data;
    nsect = (szb_bit + ss - 1) / ss; /* Start of bitmap and number of sectors */
    nb = tbl[0] + tbl[1] + tbl[2];   /* Number of clusters in-use by system */
    do {
      mem_set(buf, 0, szb_buf);
      for (i = 0; nb >= 8 && i < szb_buf; buf[i++] = 0xFF, nb -= 8)
        ;
      for (b = 1; nb != 0 && i < szb_buf; buf[i] |= b, b <<= 1, nb--)
        ;
      n = (nsect > sz_buf) ? sz_buf : nsect; /* Write the buffered data */
      if (disk_write(pdrv, buf, sect, n) != RES_OK) return FR_DISK_ERR;
      sect += n;
      nsect -= n;
    } while (nsect);

    /* Initialize the FAT */
    sect = b_fat;
    nsect = sz_fat; /* Start of FAT and number of FAT sectors */
    j = nb = cl = 0;
    do {
      mem_set(buf, 0, szb_buf);
      i = 0;         /* Clear work area and reset write index */
      if (cl == 0) { /* Set entry 0 and 1 */
        st_dword(buf + i, 0xFFFFFFF8);
        i += 4;
        cl++;
        st_dword(buf + i, 0xFFFFFFFF);
        i += 4;
        cl++;
      }
      do {                               /* Create chains of bitmap, up-case and root dir */
        while (nb != 0 && i < szb_buf) { /* Create a chain */
          st_dword(buf + i, (nb > 1) ? cl + 1 : 0xFFFFFFFF);
          i += 4;
          cl++;
          nb--;
        }
        if (nb == 0 && j < 3) nb = tbl[j++]; /* Next chain */
      } while (nb != 0 && i < szb_buf);
      n = (nsect > sz_buf) ? sz_buf : nsect; /* Write the buffered data */
      if (disk_write(pdrv, buf, sect, n) != RES_OK) return FR_DISK_ERR;
      sect += n;
      nsect -= n;
    } while (nsect);

    /* Initialize the root directory */
    mem_set(buf, 0, szb_buf);
    buf[SZDIRE * 0 + 0] = 0x83; /* 83 entry (volume label) */
    buf[SZDIRE * 1 + 0] = 0x81; /* 81 entry (allocation bitmap) */
    st_dword(buf + SZDIRE * 1 + 20, 2);
    st_dword(buf + SZDIRE * 1 + 24, szb_bit);
    buf[SZDIRE * 2 + 0] = 0x82; /* 82 entry (up-case table) */
    st_dword(buf + SZDIRE * 2 + 4, sum);
    st_dword(buf + SZDIRE * 2 + 20, 2 + tbl[0]);
    st_dword(buf + SZDIRE * 2 + 24, szb_case);
    sect = b_data + au * (tbl[0] + tbl[1]);
    nsect = au; /* Start of the root directory and number of sectors */
    do {        /* Fill root directory sectors */
      n = (nsect > sz_buf) ? sz_buf : nsect;
      if (disk_write(pdrv, buf, sect, n) != RES_OK) return FR_DISK_ERR;
      mem_set(buf, 0, ss);
      sect += n;
      nsect -= n;
    } while (nsect);

    /* Create two set of the exFAT VBR blocks */
    sect = b_vol;
    for (n = 0; n < 2; n++) {
      /* Main record (+0) */
      mem_set(buf, 0, ss);
      mem_cpy(buf + BS_JmpBoot,
              "\xEB\x76\x90"
              "EXFAT   ",
              11);                          /* Boot jump code (x86), OEM name */
      st_dword(buf + BPB_VolOfsEx, b_vol);  /* Volume offset in the physical drive [sector] */
      st_dword(buf + BPB_TotSecEx, sz_vol); /* Volume size [sector] */
      st_dword(buf + BPB_FatOfsEx, b_fat - b_vol);         /* FAT offset [sector] */
      st_dword(buf + BPB_FatSzEx, sz_fat);                 /* FAT size [sector] */
      st_dword(buf + BPB_DataOfsEx, b_data - b_vol);       /* Data offset [sector] */
      st_dword(buf + BPB_NumClusEx, n_clst);               /* Number of clusters */
      st_dword(buf + BPB_RootClusEx, 2 + tbl[0] + tbl[1]); /* Root dir cluster # */
      st_dword(buf + BPB_VolIDEx, GET_FATTIME());          /* VSN */
      st_word(buf + BPB_FSVerEx, 0x100);                   /* Filesystem version (1.00) */
      for (buf[BPB_BytsPerSecEx] = 0, i = ss; i >>= 1; buf[BPB_BytsPerSecEx]++)
        ; /* Log2 of sector size [byte] */
      for (buf[BPB_SecPerClusEx] = 0, i = au; i >>= 1; buf[BPB_SecPerClusEx]++)
        ;                                   /* Log2 of cluster size [sector] */
      buf[BPB_NumFATsEx] = 1;               /* Number of FATs */
      buf[BPB_DrvNumEx] = 0x80;             /* Drive number (for int13) */
      st_word(buf + BS_BootCodeEx, 0xFEEB); /* Boot code (x86) */
      st_word(buf + BS_55AA, 0xAA55);       /* Signature (placed here regardless of sector size) */
      for (i = sum = 0; i < ss; i++) {      /* VBR checksum */
        if (i != BPB_VolFlagEx && i != BPB_VolFlagEx + 1 && i != BPB_PercInUseEx)
          sum = xsum32(buf[i], sum);
      }
      if (disk_write(pdrv, buf, sect++, 1) != RES_OK) return FR_DISK_ERR;
      /* Extended bootstrap record (+1..+8) */
      mem_set(buf, 0, ss);
      st_word(buf + ss - 2, 0xAA55); /* Signature (placed at end of sector) */
      for (j = 1; j < 9; j++) {
        for (i = 0; i < ss; sum = xsum32(buf[i++], sum))
          ; /* VBR checksum */
        if (disk_write(pdrv, buf, sect++, 1) != RES_OK) return FR_DISK_ERR;
      }
      /* OEM/Reserved record (+9..+10) */
      mem_set(buf, 0, ss);
      for (; j < 11; j++) {
        for (i = 0; i < ss; sum = xsum32(buf[i++], sum))
          ; /* VBR checksum */
        if (disk_write(pdrv, buf, sect++, 1) != RES_OK) return FR_DISK_ERR;
      }
      /* Sum record (+11) */
      for (i = 0; i < ss; i += 4) st_dword(buf + i, sum); /* Fill with checksum value */
      if (disk_write(pdrv, buf, sect++, 1) != RES_OK) return FR_DISK_ERR;
    }

  } else
#endif /* FF_FS_EXFAT */
  {    /* Create an FAT/FAT32 volume */
    do {
      pau = au;
      /* Pre-determine number of clusters and FAT sub-type */
      if (fmt == FS_FAT32) {    /* FAT32 volume */
        if (pau == 0) {         /* au auto-selection */
          n = sz_vol / 0x20000; /* Volume size in unit of 128KS */
          for (i = 0, pau = 1; cst32[i] && cst32[i] <= n; i++, pau <<= 1)
            ; /* Get from table */
        }
        n_clst = sz_vol / pau;                   /* Number of clusters */
        sz_fat = (n_clst * 4 + 8 + ss - 1) / ss; /* FAT size [sector] */
        sz_rsv = 32;                             /* Number of reserved sectors */
        sz_dir = 0;                              /* No static directory */
        if (n_clst <= MAX_FAT16 || n_clst > MAX_FAT32) return FR_MKFS_ABORTED;
      } else {                 /* FAT volume */
        if (pau == 0) {        /* au auto-selection */
          n = sz_vol / 0x1000; /* Volume size in unit of 4KS */
          for (i = 0, pau = 1; cst[i] && cst[i] <= n; i++, pau <<= 1)
            ; /* Get from table */
        }
        n_clst = sz_vol / pau;
        if (n_clst > MAX_FAT12) {
          n = n_clst * 2 + 4; /* FAT size [byte] */
        } else {
          fmt = FS_FAT12;
          n = (n_clst * 3 + 1) / 2 + 3; /* FAT size [byte] */
        }
        sz_fat = (n + ss - 1) / ss;              /* FAT size [sector] */
        sz_rsv = 1;                              /* Number of reserved sectors */
        sz_dir = (DWORD)n_rootdir * SZDIRE / ss; /* Rootdir size [sector] */
      }
      b_fat = b_vol + sz_rsv;                    /* FAT base */
      b_data = b_fat + sz_fat * n_fats + sz_dir; /* Data base */

      /* Align data base to erase block boundary (for flash memory media) */
      n = ((b_data + sz_blk - 1) & ~(sz_blk - 1)) -
          b_data;            /* Next nearest erase block from current data base */
      if (fmt == FS_FAT32) { /* FAT32: Move FAT base */
        sz_rsv += n;
        b_fat += n;
      } else { /* FAT: Expand FAT size */
        sz_fat += n / n_fats;
      }

      /* Determine number of clusters and final check of validity of the FAT sub-type */
      if (sz_vol < b_data + pau * 16 - b_vol) return FR_MKFS_ABORTED; /* Too small volume */
      n_clst = (sz_vol - sz_rsv - sz_fat * n_fats - sz_dir) / pau;
      if (fmt == FS_FAT32) {
        if (n_clst <= MAX_FAT16) {                      /* Too few clusters for FAT32 */
          if (au == 0 && (au = pau / 2) != 0) continue; /* Adjust cluster size and retry */
          return FR_MKFS_ABORTED;
        }
      }
      if (fmt == FS_FAT16) {
        if (n_clst > MAX_FAT16) { /* Too many clusters for FAT16 */
          if (au == 0 && (pau * 2) <= 64) {
            au = pau * 2;
            continue; /* Adjust cluster size and retry */
          }
          if ((opt & FM_FAT32)) {
            fmt = FS_FAT32;
            continue; /* Switch type to FAT32 and retry */
          }
          if (au == 0 && (au = pau * 2) <= 128) continue; /* Adjust cluster size and retry */
          return FR_MKFS_ABORTED;
        }
        if (n_clst <= MAX_FAT12) {                        /* Too few clusters for FAT16 */
          if (au == 0 && (au = pau * 2) <= 128) continue; /* Adjust cluster size and retry */
          return FR_MKFS_ABORTED;
        }
      }
      if (fmt == FS_FAT12 && n_clst > MAX_FAT12)
        return FR_MKFS_ABORTED; /* Too many clusters for FAT12 */

      /* Ok, it is the valid cluster configuration */
      break;
    } while (1);

#if FF_USE_TRIM
    tbl[0] = b_vol;
    tbl[1] = b_vol + sz_vol - 1; /* Inform the device the volume area can be erased */
    disk_ioctl(pdrv, CTRL_TRIM, tbl);
#endif
    /* Create FAT VBR */
    mem_set(buf, 0, ss);
    mem_cpy(buf + BS_JmpBoot,
            "\xEB\xFE\x90"
            "MSDOS5.0",
            11);                                 /* Boot jump code (x86), OEM name */
    st_word(buf + BPB_BytsPerSec, ss);           /* Sector size [byte] */
    buf[BPB_SecPerClus] = (BYTE)pau;             /* Cluster size [sector] */
    st_word(buf + BPB_RsvdSecCnt, (WORD)sz_rsv); /* Size of reserved area */
    buf[BPB_NumFATs] = (BYTE)n_fats;             /* Number of FATs */
    st_word(buf + BPB_RootEntCnt,
            (WORD)((fmt == FS_FAT32) ? 0 : n_rootdir)); /* Number of root directory entries */
    if (sz_vol < 0x10000) {
      st_word(buf + BPB_TotSec16, (WORD)sz_vol); /* Volume size in 16-bit LBA */
    } else {
      st_dword(buf + BPB_TotSec32, sz_vol); /* Volume size in 32-bit LBA */
    }
    buf[BPB_Media] = 0xF8;              /* Media descriptor byte */
    st_word(buf + BPB_SecPerTrk, 63);   /* Number of sectors per track (for int13) */
    st_word(buf + BPB_NumHeads, 255);   /* Number of heads (for int13) */
    st_dword(buf + BPB_HiddSec, b_vol); /* Volume offset in the physical drive [sector] */
    if (fmt == FS_FAT32) {
      st_dword(buf + BS_VolID32, GET_FATTIME()); /* VSN */
      st_dword(buf + BPB_FATSz32, sz_fat);       /* FAT size [sector] */
      st_dword(buf + BPB_RootClus32, 2);         /* Root directory cluster # (2) */
      st_word(buf + BPB_FSInfo32, 1);            /* Offset of FSINFO sector (VBR + 1) */
      st_word(buf + BPB_BkBootSec32, 6);         /* Offset of backup VBR (VBR + 6) */
      buf[BS_DrvNum32] = 0x80;                   /* Drive number (for int13) */
      buf[BS_BootSig32] = 0x29;                  /* Extended boot signature */
      mem_cpy(buf + BS_VolLab32,
              "NO NAME    "
              "FAT32   ",
              19); /* Volume label, FAT signature */
    } else {
      st_dword(buf + BS_VolID, GET_FATTIME());  /* VSN */
      st_word(buf + BPB_FATSz16, (WORD)sz_fat); /* FAT size [sector] */
      buf[BS_DrvNum] = 0x80;                    /* Drive number (for int13) */
      buf[BS_BootSig] = 0x29;                   /* Extended boot signature */
      mem_cpy(buf + BS_VolLab,
              "NO NAME    "
              "FAT     ",
              19); /* Volume label, FAT signature */
    }
    st_word(buf + BS_55AA, 0xAA55); /* Signature (offset is fixed here regardless of sector size) */
    if (disk_write(pdrv, buf, b_vol, 1) != RES_OK)
      return FR_DISK_ERR; /* Write it to the VBR sector */

    /* Create FSINFO record if needed */
    if (fmt == FS_FAT32) {
      disk_write(pdrv, buf, b_vol + 6, 1); /* Write backup VBR (VBR + 6) */
      mem_set(buf, 0, ss);
      st_dword(buf + FSI_LeadSig, 0x41615252);
      st_dword(buf + FSI_StrucSig, 0x61417272);
      st_dword(buf + FSI_Free_Count, n_clst - 1); /* Number of free clusters */
      st_dword(buf + FSI_Nxt_Free, 2);            /* Last allocated cluster# */
      st_word(buf + BS_55AA, 0xAA55);
      disk_write(pdrv, buf, b_vol + 7, 1); /* Write backup FSINFO (VBR + 7) */
      disk_write(pdrv, buf, b_vol + 1, 1); /* Write original FSINFO (VBR + 1) */
    }

    /* Initialize FAT area */
    mem_set(buf, 0, (UINT)szb_buf);
    sect = b_fat;                  /* FAT start sector */
    for (i = 0; i < n_fats; i++) { /* Initialize FATs each */
      if (fmt == FS_FAT32) {
        st_dword(buf + 0, 0xFFFFFFF8); /* Entry 0 */
        st_dword(buf + 4, 0xFFFFFFFF); /* Entry 1 */
        st_dword(buf + 8, 0x0FFFFFFF); /* Entry 2 (root directory) */
      } else {
        st_dword(buf + 0, (fmt == FS_FAT12) ? 0xFFFFF8 : 0xFFFFFFF8); /* Entry 0 and 1 */
      }
      nsect = sz_fat; /* Number of FAT sectors */
      do {            /* Fill FAT sectors */
        n = (nsect > sz_buf) ? sz_buf : nsect;
        if (disk_write(pdrv, buf, sect, (UINT)n) != RES_OK) return FR_DISK_ERR;
        mem_set(buf, 0, ss);
        sect += n;
        nsect -= n;
      } while (nsect);
    }

    /* Initialize root directory (fill with zero) */
    nsect = (fmt == FS_FAT32) ? pau : sz_dir; /* Number of root directory sectors */
    do {
      n = (nsect > sz_buf) ? sz_buf : nsect;
      if (disk_write(pdrv, buf, sect, (UINT)n) != RES_OK) return FR_DISK_ERR;
      sect += n;
      nsect -= n;
    } while (nsect);
  }

  /* Determine system ID in the partition table */
  if (FF_FS_EXFAT && fmt == FS_EXFAT) {
    sys = 0x07; /* HPFS/NTFS/exFAT */
  } else {
    if (fmt == FS_FAT32) {
      sys = 0x0C; /* FAT32X */
    } else {
      if (sz_vol >= 0x10000) {
        sys = 0x06; /* FAT12/16 (large) */
      } else {
        sys = (fmt == FS_FAT16) ? 0x04 : 0x01; /* FAT16 : FAT12 */
      }
    }
  }

  /* Update partition information */
  if (FF_MULTI_PARTITION && part != 0) { /* Created in the existing partition */
    /* Update system ID in the partition table */
    if (disk_read(pdrv, buf, 0, 1) != RES_OK) return FR_DISK_ERR;  /* Read the MBR */
    buf[MBR_Table + (part - 1) * SZ_PTE + PTE_System] = sys;       /* Set system ID */
    if (disk_write(pdrv, buf, 0, 1) != RES_OK) return FR_DISK_ERR; /* Write it back to the MBR */
  } else {                 /* Created as a new single partition */
    if (!(opt & FM_SFD)) { /* Create partition table if in FDISK format */
      mem_set(buf, 0, ss);
      st_word(buf + BS_55AA, 0xAA55); /* MBR signature */
      pte = buf + MBR_Table;          /* Create partition table for single partition in the drive */
      pte[PTE_Boot] = 0;              /* Boot indicator */
      pte[PTE_StHead] = 1;            /* Start head */
      pte[PTE_StSec] = 1;             /* Start sector */
      pte[PTE_StCyl] = 0;             /* Start cylinder */
      pte[PTE_System] = sys;          /* System type */
      n = (b_vol + sz_vol) / (63 * 255);                             /* (End CHS may be invalid) */
      pte[PTE_EdHead] = 254;                                         /* End head */
      pte[PTE_EdSec] = (BYTE)(n >> 2 | 63);                          /* End sector */
      pte[PTE_EdCyl] = (BYTE)n;                                      /* End cylinder */
      st_dword(pte + PTE_StLba, b_vol);                              /* Start offset in LBA */
      st_dword(pte + PTE_SizLba, sz_vol);                            /* Size in sectors */
      if (disk_write(pdrv, buf, 0, 1) != RES_OK) return FR_DISK_ERR; /* Write it to the MBR */
    }
  }

  if (disk_ioctl(pdrv, CTRL_SYNC, 0) != RES_OK) return FR_DISK_ERR;

  return FR_OK;
}

#if FF_MULTI_PARTITION
/*-----------------------------------------------------------------------*/
/* Create Partition Table on the Physical Drive                          */
/*-----------------------------------------------------------------------*/

FRESULT f_fdisk(BYTE pdrv,        /* Physical drive number */
                const DWORD* szt, /* Pointer to the size table for each partitions */
                void* work        /* Pointer to the working buffer */
) {
  UINT i, n, sz_cyl, tot_cyl, b_cyl, e_cyl, p_cyl;
  BYTE s_hd, e_hd, *p, *buf = (BYTE*)work;
  DSTATUS stat;
  DWORD sz_disk, sz_part, s_part;

  stat = disk_initialize(pdrv);
  if (stat & STA_NOINIT) return FR_NOT_READY;
  if (stat & STA_PROTECT) return FR_WRITE_PROTECTED;
  if (disk_ioctl(pdrv, GET_SECTOR_COUNT, &sz_disk)) return FR_DISK_ERR;

  /* Determine the CHS without any consideration of the drive geometry */
  for (n = 16; n < 256 && sz_disk / n / 63 > 1024; n *= 2)
    ;
  if (n == 256) n--;
  e_hd = n - 1;
  sz_cyl = 63 * n;
  tot_cyl = sz_disk / sz_cyl;

  /* Create partition table */
  mem_set(buf, 0, FF_MAX_SS);
  p = buf + MBR_Table;
  b_cyl = 0;
  for (i = 0; i < 4; i++, p += SZ_PTE) {
    p_cyl = (szt[i] <= 100U) ? (DWORD)tot_cyl * szt[i] / 100
                             : szt[i] / sz_cyl; /* Number of cylinders */
    if (p_cyl == 0) continue;
    s_part = (DWORD)sz_cyl * b_cyl;
    sz_part = (DWORD)sz_cyl * p_cyl;
    if (i == 0) { /* Exclude first track of cylinder 0 */
      s_hd = 1;
      s_part += 63;
      sz_part -= 63;
    } else {
      s_hd = 0;
    }
    e_cyl = b_cyl + p_cyl - 1; /* End cylinder */
    if (e_cyl >= tot_cyl) return FR_INVALID_PARAMETER;

    /* Set partition table */
    p[1] = s_hd;                      /* Start head */
    p[2] = (BYTE)((b_cyl >> 2) + 1);  /* Start sector */
    p[3] = (BYTE)b_cyl;               /* Start cylinder */
    p[4] = 0x07;                      /* System type (temporary setting) */
    p[5] = e_hd;                      /* End head */
    p[6] = (BYTE)((e_cyl >> 2) + 63); /* End sector */
    p[7] = (BYTE)e_cyl;               /* End cylinder */
    st_dword(p + 8, s_part);          /* Start sector in LBA */
    st_dword(p + 12, sz_part);        /* Number of sectors */

    /* Next partition */
    b_cyl += p_cyl;
  }
  st_word(p, 0xAA55);

  /* Write it to the MBR */
  return (disk_write(pdrv, buf, 0, 1) != RES_OK || disk_ioctl(pdrv, CTRL_SYNC, 0) != RES_OK)
             ? FR_DISK_ERR
             : FR_OK;
}

#endif /* FF_MULTI_PARTITION */
#endif /* FF_USE_MKFS && !FF_FS_READONLY */

#if FF_USE_STRFUNC
/*-----------------------------------------------------------------------*/
/* Get a String from the File                                            */
/*-----------------------------------------------------------------------*/

TCHAR* f_gets(TCHAR* buff, /* Pointer to the string buffer to read */
              int len,     /* Size of string buffer (characters) */
              FIL* fp      /* Pointer to the file object */
) {
  int n = 0;
  TCHAR c, *p = buff;
  BYTE s[2];
  UINT rc;

  while (n < len - 1) {          /* Read characters until buffer gets filled */
#if FF_LFN_UNICODE && FF_USE_LFN /* Unicode API */
#if FF_STRF_ENCODE == 3          /* Read a character in UTF-8 */
    f_read(fp, s, 1, &rc);
    if (rc != 1) break;
    c = s[0];
    if (c >= 0x80) {
      if (c < 0xC0) continue; /* Skip stray trailer */
      if (c < 0xE0) {         /* Two-byte sequence (0x80-0x7FF) */
        f_read(fp, s, 1, &rc);
        if (rc != 1) break;
        c = (c & 0x1F) << 6 | (s[0] & 0x3F);
        if (c < 0x80) c = '?'; /* Reject invalid code range */
      } else {
        if (c < 0xF0) { /* Three-byte sequence (0x800-0xFFFF) */
          f_read(fp, s, 2, &rc);
          if (rc != 2) break;
          c = c << 12 | (s[0] & 0x3F) << 6 | (s[1] & 0x3F);
          if (c < 0x800) c = '?'; /* Reject invalid code range */
        } else {                  /* Reject four-byte sequence */
          c = '?';
        }
      }
    }
#elif FF_STRF_ENCODE == 2 /* Read a character in UTF-16BE */
    f_read(fp, s, 2, &rc);
    if (rc != 2) break;
    c = s[1] + (s[0] << 8);
#elif FF_STRF_ENCODE == 1 /* Read a character in UTF-16LE */
    f_read(fp, s, 2, &rc);
    if (rc != 2) break;
    c = s[0] + (s[1] << 8);
#else                     /* Read a character in ANSI/OEM */
    f_read(fp, s, 1, &rc);
    if (rc != 1) break;
    c = s[0];
    if (dbc_1st((BYTE)c)) {
      f_read(fp, s, 1, &rc);
      if (rc != 1) break;
      c = (c << 8) + s[0];
    }
    c = ff_oem2uni(c, CODEPAGE); /* OEM -> Unicode */
    if (!c) c = '?';
#endif
#else /* ANSI/OEM API: Read a character without conversion */
    f_read(fp, s, 1, &rc);
    if (rc != 1) break;
    c = s[0];
#endif
    if (FF_USE_STRFUNC == 2 && c == '\r') continue; /* Strip '\r' */
    *p++ = c;
    n++;
    if (c == '\n') break; /* Break on EOL */
  }
  *p = 0;
  return n ? buff : 0; /* When no data read (eof or error), return with error. */
}

#if !FF_FS_READONLY
#include <stdarg.h>
/*-----------------------------------------------------------------------*/
/* Put a Character to the File                                           */
/*-----------------------------------------------------------------------*/

typedef struct {
  FIL* fp;       /* Ptr to the writing file */
  int idx, nchr; /* Write index of buf[] (-1:error), number of chars written */
  BYTE buf[64];  /* Write buffer */
} putbuff;

static void putc_bfd(/* Buffered write with code conversion */
                     putbuff* pb, TCHAR c) {
  UINT bw;
  int i;

  if (FF_USE_STRFUNC == 2 && c == '\n') { /* LF -> CRLF conversion */
    putc_bfd(pb, '\r');
  }

  i = pb->idx; /* Write index of pb->buf[] */
  if (i < 0) return;

#if FF_LFN_UNICODE && FF_USE_LFN /* Unicode API */
#if FF_STRF_ENCODE == 3          /* Write a character in UTF-8 */
  if (c < 0x80) {                /* 7-bit */
    pb->buf[i++] = (BYTE)c;
  } else {
    if (c < 0x800) { /* 11-bit */
      pb->buf[i++] = (BYTE)(0xC0 | c >> 6);
    } else { /* 16-bit */
      pb->buf[i++] = (BYTE)(0xE0 | c >> 12);
      pb->buf[i++] = (BYTE)(0x80 | (c >> 6 & 0x3F));
    }
    pb->buf[i++] = (BYTE)(0x80 | (c & 0x3F));
  }
#elif FF_STRF_ENCODE == 2 /* Write a character in UTF-16BE */
  pb->buf[i++] = (BYTE)(c >> 8);
  pb->buf[i++] = (BYTE)c;
#elif FF_STRF_ENCODE == 1 /* Write a character in UTF-16LE */
  pb->buf[i++] = (BYTE)c;
  pb->buf[i++] = (BYTE)(c >> 8);
#else                     /* Write a character in ANSI/OEM */
  c = ff_uni2oem(c, CODEPAGE); /* Unicode -> OEM */
  if (!c) c = '?';
  if (c >= 0x100) pb->buf[i++] = (BYTE)(c >> 8);
  pb->buf[i++] = (BYTE)c;
#endif
#else /* ANSI/OEM API: Write a character without conversion */
  pb->buf[i++] = (BYTE)c;
#endif

  if (i >= (int)(sizeof pb->buf) - 3) { /* Write buffered characters to the file */
    f_write(pb->fp, pb->buf, (UINT)i, &bw);
    i = (bw == (UINT)i) ? 0 : -1;
  }
  pb->idx = i;
  pb->nchr++;
}

static int putc_flush(/* Flush left characters in the buffer */
                      putbuff* pb) {
  UINT nw;

  if (pb->idx >= 0 /* Flush buffered characters to the file */
      && f_write(pb->fp, pb->buf, (UINT)pb->idx, &nw) == FR_OK && (UINT)pb->idx == nw)
    return pb->nchr;
  return EOF;
}

static void putc_init(/* Initialize write buffer */
                      putbuff* pb, FIL* fp) {
  pb->fp = fp;
  pb->nchr = pb->idx = 0;
}

int f_putc(TCHAR c, /* A character to be output */
           FIL* fp  /* Pointer to the file object */
) {
  putbuff pb;

  putc_init(&pb, fp);
  putc_bfd(&pb, c); /* Put the character */
  return putc_flush(&pb);
}

/*-----------------------------------------------------------------------*/
/* Put a String to the File                                              */
/*-----------------------------------------------------------------------*/

int f_puts(const TCHAR* str, /* Pointer to the string to be output */
           FIL* fp           /* Pointer to the file object */
) {
  putbuff pb;

  putc_init(&pb, fp);
  while (*str) putc_bfd(&pb, *str++); /* Put the string */
  return putc_flush(&pb);
}

/*-----------------------------------------------------------------------*/
/* Put a Formatted String to the File                                    */
/*-----------------------------------------------------------------------*/

int f_printf(FIL* fp,          /* Pointer to the file object */
             const TCHAR* fmt, /* Pointer to the format string */
             ...               /* Optional arguments... */
) {
  va_list arp;
  putbuff pb;
  BYTE f, r;
  UINT i, j, w;
  DWORD v;
  TCHAR c, d, str[32], *p;

  putc_init(&pb, fp);

  va_start(arp, fmt);

  for (;;) {
    c = *fmt++;
    if (c == 0) break; /* End of string */
    if (c != '%') {    /* Non escape character */
      putc_bfd(&pb, c);
      continue;
    }
    w = f = 0;
    c = *fmt++;
    if (c == '0') { /* Flag: '0' padding */
      f = 1;
      c = *fmt++;
    } else {
      if (c == '-') { /* Flag: left justified */
        f = 2;
        c = *fmt++;
      }
    }
    while (IsDigit(c)) { /* Precision */
      w = w * 10 + c - '0';
      c = *fmt++;
    }
    if (c == 'l' || c == 'L') { /* Prefix: Size is long int */
      f |= 4;
      c = *fmt++;
    }
    if (!c) break;
    d = c;
    if (IsLower(d)) d -= 0x20;
    switch (d) { /* Type is... */
      case 'S':  /* String */
        p = va_arg(arp, TCHAR*);
        for (j = 0; p[j]; j++)
          ;
        if (!(f & 2)) { /* Right pad */
          while (j++ < w) putc_bfd(&pb, ' ');
        }
        while (*p) putc_bfd(&pb, *p++);     /* String body */
        while (j++ < w) putc_bfd(&pb, ' '); /* Left pad */
        continue;

      case 'C': /* Character */
        putc_bfd(&pb, (TCHAR)va_arg(arp, int));
        continue;

      case 'B': /* Binary */
        r = 2;
        break;

      case 'O': /* Octal */
        r = 8;
        break;

      case 'D': /* Signed decimal */
      case 'U': /* Unsigned decimal */
        r = 10;
        break;

      case 'X': /* Hexdecimal */
        r = 16;
        break;

      default: /* Unknown type (pass-through) */
        putc_bfd(&pb, c);
        continue;
    }

    /* Get an argument and put it in numeral */
    v = (f & 4) ? (DWORD)va_arg(arp, long)
                : ((d == 'D') ? (DWORD)(long)va_arg(arp, int) : (DWORD)va_arg(arp, unsigned int));
    if (d == 'D' && (v & 0x80000000)) {
      v = 0 - v;
      f |= 8;
    }
    i = 0;
    do {
      d = (TCHAR)(v % r);
      v /= r;
      if (d > 9) d += (c == 'x') ? 0x27 : 0x07;
      str[i++] = d + '0';
    } while (v && i < sizeof str / sizeof *str);
    if (f & 8) str[i++] = '-';
    j = i;
    d = (f & 1) ? '0' : ' ';
    if (!(f & 2)) {
      while (j++ < w) putc_bfd(&pb, d); /* Right pad */
    }
    do {
      putc_bfd(&pb, str[--i]); /* Number body */
    } while (i);
    while (j++ < w) putc_bfd(&pb, d); /* Left pad */
  }

  va_end(arp);

  return putc_flush(&pb);
}

#endif /* !FF_FS_READONLY */
#endif /* FF_USE_STRFUNC */

#if FF_CODE_PAGE == 0
/*-----------------------------------------------------------------------*/
/* Set Active Codepage for the Path Name                                 */
/*-----------------------------------------------------------------------*/

FRESULT f_setcp(WORD cp /* Value to be set as active code page */
) {
  static const WORD validcp[] = {437, 720, 737, 771, 775, 850, 852, 857, 860, 861, 862,
                                 863, 864, 865, 866, 869, 932, 936, 949, 950, 0};
  static const BYTE* const tables[] = {Ct437, Ct720, Ct737, Ct771, Ct775, Ct850, Ct852,
                                       Ct857, Ct860, Ct861, Ct862, Ct863, Ct864, Ct865,
                                       Ct866, Ct869, Dc932, Dc936, Dc949, Dc950, 0};
  UINT i;

  for (i = 0; validcp[i] != 0 && validcp[i] != cp; i++)
    ; /* Find the code page */
  if (validcp[i] != cp) return FR_INVALID_PARAMETER;

  CodePage = cp;
  if (cp >= 900) { /* DBCS */
    ExCvt = 0;
    DbcTbl = tables[i];
  } else { /* SBCS */
    ExCvt = tables[i];
    DbcTbl = 0;
  }
  return FR_OK;
}
#endif /* FF_CODE_PAGE == 0 */
